CN109192009B - University mathematics parabola demonstration teaching optimization method - Google Patents

Abstract

The invention belongs to the technical field of mathematics teaching, in particular to an optimization method for university mathematics parabola demonstration teaching, which comprises the following steps: placing a demonstration device in front of a classroom blackboard, and placing a mobile phone for image acquisition in front of the demonstration device; The parabolic trajectory of the steel ball at different launch angles is shown to the students through the demonstration device; during the demonstration of the parabolic trajectory, the moving position of the steel ball is collected by taking pictures continuously through the mobile phone, and the signal is sent to the computer to calculate the position of the steel ball. The speed of each position, and draw the speed curve; display the speed curve and the motion trajectory of the steel ball through the display screen; decompose the speed curve on the display screen through the computer, calculate the horizontal movement speed and the vertical movement speed, To understand the nature of parabolic motion. The invention deepens students' understanding and ensures the quality of teaching.

Description

An Optimization Method for Demonstration Teaching of University Mathematical Parabola

technical field

The invention belongs to the technical field of mathematics teaching, in particular to a teaching optimization method for university mathematics parabola demonstration.

Background technique

In the plane, the locus of a point equidistant from a fixed point and a fixed line is called a parabola. At present, in mathematics teaching, teachers need to explain to students how the formation process of parabola is reflected through mathematical expressions. Due to the specific abstraction of mathematical thinking, in addition to the fact that different students have different understandings, in teaching In the process of learning, it is often difficult to understand the problems of the teaching process that is boring and the effect is not good; the parabolic trajectory shown by the experiment only exists in the moment of movement, it is difficult for the students to form a long-term intuitive feeling, and it is impossible to realize the rapidity of the movement trajectory. analyze.

SUMMARY OF THE INVENTION

In order to make up for the deficiencies of the prior art, the present invention proposes an optimization method for university mathematics parabola demonstration teaching. The present invention is mainly used to solve the problems of incomprehension and insufficient follow-up motion analysis in the parabolic teaching process.

The technical solution adopted by the present invention to solve the technical problem is: a method for optimizing teaching of university mathematics parabola demonstration teaching according to the present invention, and the method comprises the following steps:

S1: Put the demonstration device in front of the classroom blackboard, and place a mobile phone for image acquisition in front of the demonstration device;

S2: After S1 is completed, students will be shown the parabolic trajectory of the steel ball at different launching angles through the demonstration device, and the launching angle will be automatically adjusted by the demonstration device, so that the steel ball will move in different parabolic trajectories, which improves the accuracy and efficiency;

S3: During the demonstration of the parabolic trajectory in S2, the moving position of the steel ball is collected by taking pictures continuously through the mobile phone, and the signal is sent to the computer to calculate the speed of the steel ball at each position, and draw the speed curve. The distance of the upper point is fixed by the time interval of continuous photography, so as to analyze the speed of the steel ball at each position;

S4: Display the speed curve in S3 and the motion trajectory of the steel ball through the display screen;

S5: The speed curve is decomposed on the display screen by the computer, and the horizontal motion speed and the vertical motion speed are calculated, so as to understand the essence of parabolic motion;

Wherein, the demonstration device used in this method includes a fixed plate, a connecting plate, a turntable, a launch cylinder, a controller and a computer, the fixed plate is placed vertically, and the bottom end of the fixed plate is vertically upwardly provided with a groove, and the groove is located in the fixed plate. Inside the plate, the front end surface of the fixed plate is evenly provided with through holes, the through holes communicate with the grooves inside the fixed plate, and a magnetic switch and an LED light are arranged in the through holes; the magnetic switch is electrically connected with the controller; the control The connecting plate is vertically arranged below the fixing plate; the turntable is installed on the connecting plate through a rotation of the rotating shaft, the turntable can rotate in the vertical plane of the connecting plate, and the turntable is located below the fixing plate; The launching cylinder is installed on the turntable by rotating the second shaft. The launching cylinder is used to throw the steel balls. The middle position of the upper end face of the launching cylinder is provided with a cylindrical sliding groove along the direction of its own axis. The cylindrical sliding groove stores the steel balls. The cylinder is located just below the groove of the fixed plate. The diameter of the cylindrical sliding groove of the launch cylinder is the same as the width of the groove of the fixed plate. A launch unit is arranged in the launch cylinder, and the launch unit is used to push out the steel ball in the launch cylinder, so that the steel The ball moves in a parabolic trajectory in the groove of the fixed plate. During the movement of the steel ball in the groove of the fixed plate, the magnetic switch in the through hole on the moving trajectory is triggered to light up the LED light; The axis is horizontal, the second rotating shaft is fixed on the upper end of the launch cylinder, and the axis of the second rotating shaft is located in the horizontal plane where the open end face of the launching cylinder is located; wherein,

The launching unit includes a push plate, a spring, an electromagnet, a rotating plate, a worm and a motor. The push plate is located in the cylindrical sliding groove of the launch cylinder, and the push plate is made of ferromagnetic material. Inside the launch cylinder, a spring is used to provide elastic force to make the push plate move upward along the sliding groove; the electromagnet is built into the bottom of the launch cylinder, and the electromagnet is used to make the push plate move down along the sliding groove through the action of magnetic force The rotating plate is fixedly installed at the bottom end of the launching cylinder, the rotating plate is arc-shaped, the center of curvature of the rotating plate coincides with the center point of the exit of the sliding groove on the upper end face of the launching cylinder, and the lower surface of the rotating plate is provided with a toothed structure; The worm is horizontally installed on the turntable, the worm is located under the rotating plate, and the worm is engaged with the toothed structure of the rotating plate; the motor is installed on the turntable, the motor is used to drive the worm to rotate, and the motor is electrically connected with the controller. When the parabola demonstration is required, the electromagnet is powered off, and the push plate moves up along the sliding groove of the launch cylinder under the elastic force of the spring I to push the steel ball out. After the steel ball is pushed out of the launch cylinder, it enters the groove of the fixed plate. , and perform parabolic trajectory motion in the groove. During the movement of the steel ball in the groove, the magnetic switch in the through hole on the motion trajectory is triggered to light up the corresponding LED light, so that the LED light on the motion trajectory of the steel ball is lit. Light up to form an intuitive parabolic trajectory; when it is necessary to adjust the launch angle of the steel ball to study the parabolic trajectory, the motor works, and the worm gear drives the launch cylinder to rotate around the second axis, thus changing the time when the steel ball is pushed out of the launch cylinder. Since the axis of the second shaft is located in the horizontal plane where the open end face of the launch cylinder is located, the position of the steel ball when it flies out of the launch cylinder is the same every time, which ensures the research on the parabolic trajectory under the control of a single variable. .

The fixing plate is provided with a guiding plate at the bottom of the groove, and a receiving plate is horizontally arranged below the fixing plate; The position of the plate close to the right end face is vertically arranged with a discharge hole; the receiving plate is located on the right side of the launching cylinder, the right end of the receiving plate is hinged on the connecting plate, and the receiving plate is in contact with the guide plate when it is in a horizontal state, and the receiving plate is discharged An inductor is arranged below the hole, an electromagnet 2 is arranged near the left end of the bearing plate, a magnet block 1 is arranged on the guide plate at a position corresponding to the second electromagnet, and a spring 2 is arranged under the bearing plate, and one end of the spring 2 is connected to the bearing The lower surface of the plate is connected, and the other end of the second spring is connected with the connecting plate. The second spring is used to swing the bearing plate downward, and the connection between the bearing plate and the turntable is realized by a connecting rod; one end of the connecting rod is hinged on the bearing plate. , the other end of the connecting rod is hinged with the turntable; the connecting plate is also provided with a limit plate; the limit plate is used to limit the downward swinging angle of the receiving plate. After the steel ball completes the parabolic motion in the groove of the fixed plate, it falls to the guide plate. Since the guide plate is an inclined plane, the steel ball moves along the guide plate to the position of the discharge hole, and falls from the discharge hole to the receiving plate. The sensor generates a signal, and the second electromagnet is powered off. Under the action of the second spring, the receiving plate swings down around the hinge point at the right end. The steel ball on the receiving plate moves to the left along the receiving plate, and the receiving plate swings while passing through. The connecting rod pushes the turntable to rotate clockwise around the rotating shaft, so that the launch cylinder rotates to the left end of the receiving plate and is close to the left end of the receiving plate. The steel ball can be recovered automatically, and the existence of the limit plate keeps the receiving plate at the same angular position after swinging downward, which is beneficial to the smooth recovery of the steel ball.

The inner side of the upper end of the launch cylinder is provided with a second magnet block. The existence of the second magnet block can magnetically attract the steel balls flying out of the left end of the receiving plate, so that the steel balls fall into the launch tube smoothly.

A display screen is arranged on the front end surface of the fixing plate; the display screen is transparent, and the display screen is electrically connected with the computer. The transparent display screen can not only make the lighted LED lights pass through the display screen, so as to give people an intuitive display; at the same time, the computer displays the movement trajectory of the steel ball on the display screen through electronic signals, and makes the emission angle adjusted. The parabolic electron trajectories of multiple experiments are stored on the display for a long time, which is convenient for intuitive comparison and analysis.

A ring-shaped electromagnet is arranged near the upper end of the launching cylinder, and a conical spring is also sleeved on the launching cylinder. When the receiving plate swings downward, the launch cylinder rotates synchronously to the direction close to the left end of the receiving plate, the ring electromagnet is powered off, the conical spring extends upward to enlarge the opening, and the steel balls entering the conical spring can smoothly fall into the launching In the cylinder, the probability of the steel ball entering the launch cylinder is increased, and the recovery of the steel ball is ensured.

A cylinder is arranged between the limit plate and the receiving plate; both ends of the air cylinder are hinged on the limit plate and the receiving plate respectively; the air cylinder is connected with the air storage tank through an air pipe. The existence of the cylinder can buffer the bearing plate when it swings downward, and avoid that the bearing plate moves too fast under the elastic force of the second spring, causing the steel ball to fall off the bearing plate. The compressed air cylinder generates compressed air. When the recovery of the steel balls is completed, the compressed air in the air storage tank pushes the cylinder to move. At the same time, the second electromagnet is energized, under the thrust of the cylinder and the magnetic force of the second electromagnet and the magnet block 1, the connection is made. The plate is back in contact with the guide plate, ready for the next experiment.

The beneficial effects of the present invention are as follows:

1. A kind of university mathematics parabola demonstration teaching optimization method of the present invention, the present invention collects the parabolic motion trajectory of the steel ball by setting the demonstration device and taking continuous pictures, and then analyzes and calculates the picture by the computer, and passes The display screen shows the speed curve and motion trajectory, so that the students can form an intuitive understanding, and further analyze the speed curve in time, which deepens the students' understanding and ensures the quality of teaching.

2. A kind of university mathematics parabola demonstration teaching optimization method of the present invention, the demonstration device adopted by the present invention is to set the launching unit on the launching cylinder, and use the worm gear and worm drive to make the rotating plate fixed on the launching cylinder with a toothed structure to rotate. , thereby driving the launch cylinder to rotate around the second rotating shaft. Since the axis of the rotating shaft two is located in the horizontal plane where the open end face of the launching cylinder is located, the position of the steel ball is the same every time it flies out of the launching cylinder. The control of the thrust of the steel ball ensures precise adjustment, realizes the control of a single variable, improves the scientificity of subsequent motion analysis, and is conducive to discovering the law of parabola motion.

3. The teaching optimization method of university mathematics parabola demonstration according to the present invention, the demonstration device adopted in the present invention makes the steel balls launched move along the guide plate to the receiving plate by setting the guide plate and the receiving plate, and by disconnecting the The second electromagnet makes the receiving plate swing, and the connecting rod is used to rotate the turntable while the receiving plate is swinging, so that the launching tube is close to the receiving plate, and the steel balls on the receiving plate fall into the launching tube smoothly, realizing the recovery of the steel balls and improving the the efficiency of teaching.

Description of drawings

Fig. 1 is the method flow chart of the present invention;

Fig. 2 is the front view of the present invention;

Fig. 3 is the left side view of the present invention;

Fig. 4 is the partial enlarged view of A place in Fig. 2 of the present invention;

In the figure: fixed plate 1, connecting plate 2, turntable 3, launch tube 4, groove 11, magnetic switch 12, LED light 13, rotating shaft 1 31, rotating shaft 2 41, steel ball 5, sliding groove 42, launching unit 6, Push plate 61, electromagnet one 62, rotating plate 63, worm 64, motor 65, guide plate 14, receiving plate 15, discharge hole 141, electromagnet two 16, magnet block one 17, connecting rod 18, limit plate 19 , Magnet block two 43, display screen 7, ring electromagnet 8, conical spring 9, cylinder 10.

Detailed ways

A method for optimizing teaching of university mathematics parabola demonstration teaching according to an embodiment of the present invention will be described as follows using FIG. 1 to FIG. 4 .

As shown in FIG. 1-FIG. 3, a method for optimizing teaching of university mathematics parabola demonstration teaching according to the present invention, the method includes the following steps:

S1: Put the demonstration device in front of the classroom blackboard, and place a mobile phone for image acquisition in front of the demonstration device;

S2: After S1 is completed, students will be shown the parabolic trajectory of the steel ball at different launching angles through the demonstration device, and the launching angle will be automatically adjusted by the demonstration device, so that the steel ball will move in different parabolic trajectories, which improves the accuracy and efficiency;

S3: During the demonstration of the parabolic trajectory in S2, the moving position of the steel ball is collected by taking pictures continuously through the mobile phone, and the signal is sent to the computer to calculate the speed of the steel ball at each position, and draw the speed curve. The distance of the upper point is fixed by the time interval of continuous photography, so as to analyze the speed of the steel ball at each position;

S4: Display the speed curve in S3 and the motion trajectory of the steel ball through the display screen;

S5: The speed curve is decomposed on the display screen by the computer, and the horizontal motion speed and the vertical motion speed are calculated, so as to understand the essence of parabolic motion;

Wherein, the demonstration device used in this method includes a fixed plate 1, a connecting plate 2, a turntable 3, a launch cylinder 4, a controller and a computer, the fixed plate 1 is placed vertically, and the bottom end of the fixed plate 1 is vertically upwardly provided with a concave The groove 11 and the groove 11 are located inside the fixing plate 1. The front end surface of the fixing plate 1 is evenly provided with through holes. The through holes communicate with the groove 11 inside the fixing plate 1, and the magnetic switches 12 and the LED lights 13 are arranged in the through holes. The magnetic switch 12 is electrically connected with the controller; the controller is connected with the computer; the connecting plate 2 is vertically arranged below the fixed plate 1; , the turntable 3 can be rotated in the vertical plane of the connecting plate 2, and the turntable 3 is located below the fixed plate 1; the launch cylinder 4 is rotated and installed on the turntable 3 through the second rotating shaft 41, and the launch cylinder 4 is used to make the steel ball 5 cast Out, the middle position of the upper end face of the launching cylinder 4 is provided with a cylindrical sliding groove 42 along the direction of its own axis. The cylindrical sliding groove 42 stores the steel balls 5. The launching cylinder 4 is located directly below the groove 11 of the fixed plate 1. The diameter of the cylindrical sliding groove 42 is the same as the width of the groove 11 of the fixed plate 1. The launching unit 6 is arranged in the launching cylinder 4, and the launching unit 6 is used to push out the steel ball 5 in the launching cylinder 4, so that the steel ball 5 is in the fixed plate. The groove 11 of 1 moves in a parabolic trajectory. During the movement of the steel ball 5 in the groove 11 of the fixed plate 1, the magnetic switch 12 in the through hole on the movement trajectory is triggered to light up the LED light 13; the The axis of the second rotating shaft 41 is horizontal, the second rotating shaft 41 is fixed on the upper end of the launching cylinder 4, and the axis of the second rotating shaft 41 is located in the horizontal plane where the open end face of the launching cylinder 4 is located; wherein,

The launching unit 6 includes a push plate 61, a spring 1, an electromagnet 62, a rotating plate 63, a worm 64 and a motor 65. The push plate 61 is located in the cylindrical sliding groove 42 of the launch cylinder 4. The push plate 61 is made of iron. Magnetic material; the spring one is located inside the launch cylinder 4, the spring one is used to provide elastic force to make the push plate 61 move upward along the sliding groove 42; the electromagnet one 62 is built in the bottom of the launch cylinder 4, the electromagnet one 62 is used to make the push plate 61 move downward along the sliding groove 42 through the action of magnetic force; the rotating plate 63 is fixedly installed on the bottom end of the launching cylinder 4, the rotating plate 63 is arc-shaped, and the center of curvature of the rotating plate 63 is the same as the launching cylinder. 4. The center point of the exit of the sliding groove 42 on the upper end surface is coincident, and the lower surface of the rotating plate 63 is provided with a toothed structure; The motor 65 is installed on the turntable 3, the motor 65 is used to drive the worm 64 to rotate, and the motor 65 is electrically connected to the controller. When the parabola demonstration needs to be performed, the electromagnet 1 62 is powered off, and the push plate 61 moves upward along the sliding groove 42 of the launch cylinder 4 under the elastic force of the spring 1 to push the steel ball 5 out. After the steel ball 5 is pushed out of the launch cylinder 4 Enter into the groove 11 of the fixed plate 1, and perform a parabolic trajectory movement in the groove 11. During the movement of the steel ball 5 in the groove 11, the magnetic switch 12 in the through hole on the movement trajectory is triggered to make the corresponding LED The light 13 is lit, so that the LED light 13 on the motion trajectory of the steel ball 5 is lit, forming an intuitive parabolic motion trajectory; when the launch angle of the steel ball 5 needs to be adjusted to study the parabolic trajectory, the motor 65 works, and is driven by the worm gear 64 The launching cylinder 4 is rotated around the second rotating shaft 41, thereby changing the initial angle when the steel ball 5 is pushed out of the launching cylinder 4. Since the axis of the rotating shaft 2 41 is located in the horizontal plane where the open end face of the launching cylinder 4 is located, the steel ball 5 The position is the same each time it flies out of the launch cylinder 4, which ensures the study of the parabolic trajectory under the control of a single variable.

As shown in FIG. 2 , the fixing plate 1 is provided with a guide plate 14 at the bottom of the groove 11 , and a receiving plate 15 is horizontally arranged below the fixing plate 1 ; The upper surface of 14 is inclined with a high left and a low right, and a discharge hole 141 is vertically arranged at the position of the guide plate 14 close to the right end surface; On the plate 2, the receiving plate 15 is in contact with the guide plate 14 when it is in a horizontal state. The receiving plate 15 is provided with an inductor below the discharge hole 141. The receiving plate 15 is provided with an electromagnet 2 16 near the left end. The position corresponding to the second electromagnet 16 is provided with a magnet block 1 17 , and a second spring is arranged below the receiving plate 15 . Second, it is used to swing the receiving plate 15 downward, and the connection between the receiving plate 15 and the turntable 3 is realized by a connecting rod 18; one end of the connecting rod 18 is hinged on the receiving plate 15, and the other end of the connecting rod 18 is hinged with the turntable 3; The connecting plate 2 is also provided with a limiting plate 19 ; the limiting plate 19 is used to limit the downward swinging angle of the receiving plate 15 . The steel ball 5 falls onto the guide plate 14 after completing the parabolic motion in the groove 11 of the fixed plate 1. Since the guide plate 14 is an inclined plane, the steel ball 5 moves along the guide plate 14 to the position of the discharge hole 141, and discharges from the discharge hole 141. The hole 141 falls into the receiving plate 15 to make the sensor generate a signal, and the second electromagnet 16 is powered off. Under the action of the second spring, the receiving plate 15 swings down around the hinge point at the right end, and the steel ball 5 on the receiving plate 15 Moving to the left along the receiving plate 15, the receiving plate 15 swings and at the same time pushes the turntable 3 to rotate clockwise around the rotating shaft 1 31 through the connecting rod 18, so that the launching cylinder 4 rotates to the left end of the receiving plate 15 and approaches the left end of the receiving plate 15, The steel balls 5 fly out from the left end of the receiving plate 15 under the action of gravity and then fall into the launch cylinder 4, which realizes the automatic recovery of the steel balls 5. The existence of the limit plate 19 makes the receiving plate 15 swing downward and maintain the same position. The angular position is conducive to the smooth recovery of the steel ball 5 .

As shown in FIG. 2 , a second magnet block 43 is provided on the inner side of the upper end of the launching cylinder 4 . The existence of the second magnet block 43 can magnetically attract the steel balls 5 flying out of the left end of the receiving plate 15 , so that the steel balls 5 fall into the launch cylinder 4 smoothly.

As shown in FIG. 3 , a display screen 7 is provided on the front surface of the fixing plate 1 ; the display screen 7 is transparent, and the display screen 7 is electrically connected to the computer. The transparent display screen 7 can make the light of the lighted LED lights 13 pass through the display screen 7, so as to give people an intuitive display; at the same time, the computer displays the movement trajectory of the steel ball 5 on the display screen 7 through electronic signals, and makes the The parabolic electron trajectories of multiple experiments after adjusting the emission angle are stored on the display screen 7 for a long time, which is convenient for intuitive comparison and analysis.

As shown in Fig. 2 and Fig. 4 , a ring-shaped electromagnet 8 is arranged near the upper end of the launching cylinder 4, and a conical spring 9 is also sleeved on the launching cylinder 4. The shape spring 9 is made of ferromagnetic material. When the receiving plate 15 swings downward, the launch cylinder 4 rotates synchronously to the direction close to the left end of the receiving plate 15, the ring electromagnet 8 is powered off, the conical spring 9 extends upward to enlarge the opening, and the steel balls entering the conical spring 9 5 can smoothly fall into the launch tube 4 , which increases the probability of the steel ball 5 entering the launch tube 4 and ensures the recovery of the steel ball 5 .

As shown in FIG. 2 , a cylinder 10 is arranged between the limiting plate 19 and the receiving plate 15 ; both ends of the cylinder 10 are hinged on the limiting plate 19 and the receiving plate 15 respectively; The gas tank is connected. The existence of the cylinder 10 can buffer the bearing plate 15 when it swings downward, and avoid that the bearing plate 15 moves too fast under the elastic force of the spring 2 and causes the steel ball 5 to fall off the bearing plate 15. At the same time, the bearing plate 15 carries the steel ball 5. When the ball 5 swings downward, the compressed air cylinder 10 generates compressed air. When the recovery of the steel ball 5 is completed, the compressed air in the air storage tank pushes the cylinder 10 to move. Under the action of the magnetic force of the iron 2 16 and the magnet block 1 17, the receiving plate 15 is brought into contact with the guide plate 14 again, which is ready for the next experiment.

The specific process is as follows:

When the parabola demonstration needs to be performed, the electromagnet 1 62 is powered off, and the push plate 61 moves upward along the sliding groove 42 of the launch cylinder 4 under the elastic force of the spring 1 to push the steel ball 5 out. After the steel ball 5 is pushed out of the launch cylinder 4 Enter into the groove 11 of the fixed plate 1, and perform a parabolic trajectory movement in the groove 11. During the movement of the steel ball 5 in the groove 11, the magnetic switch 12 in the through hole on the movement trajectory is triggered to make the corresponding LED The light 13 is lit, so that the LED light 13 on the motion trajectory of the steel ball 5 is lit, forming an intuitive parabolic motion trajectory; when the launch angle of the steel ball 5 needs to be adjusted to study the parabolic trajectory, the motor 65 works, and is driven by the worm gear 64 The launching cylinder 4 is rotated around the second rotating shaft 41, thereby changing the initial angle when the steel ball 5 is pushed out of the launching cylinder 4. Since the axis of the rotating shaft 2 41 is located in the horizontal plane where the open end face of the launching cylinder 4 is located, the steel ball 5 The position is the same each time it flies out of the launch cylinder 4, which ensures the study of the parabolic trajectory under the control of a single variable.

The steel ball 5 falls onto the guide plate 14 after completing the parabolic motion in the groove 11 of the fixed plate 1. Since the guide plate 14 is an inclined plane, the steel ball 5 moves along the guide plate 14 to the position of the discharge hole 141, and discharges from the discharge hole 141. The hole 141 falls into the receiving plate 15 to make the sensor generate a signal, and the second electromagnet 16 is powered off. Under the action of the second spring, the receiving plate 15 swings down around the hinge point at the right end, and the steel ball 5 on the receiving plate 15 Moving to the left along the receiving plate 15, the receiving plate 15 swings and at the same time pushes the turntable 3 to rotate clockwise around the rotating shaft 1 31 through the connecting rod 18, so that the launching cylinder 4 rotates to the left end of the receiving plate 15 and approaches the left end of the receiving plate 15, The steel balls 5 fly out from the left end of the receiving plate 15 under the action of gravity and then fall into the launch cylinder 4, which realizes the automatic recovery of the steel balls 5. The existence of the limit plate 19 makes the receiving plate 15 swing downward and maintain the same position. The angular position is conducive to the smooth recovery of the steel ball 5 .

The transparent display screen 7 can make the light of the lighted LED lights 13 pass through the display screen 7, so as to give people an intuitive display; at the same time, the computer displays the movement trajectory of the steel ball 5 on the display screen 7 through electronic signals, and makes the The parabolic electron trajectories of multiple experiments after adjusting the emission angle are stored on the display screen 7 for a long time, which is convenient for intuitive comparison and analysis.

When the receiving plate 15 swings downward, the launch cylinder 4 rotates synchronously to the direction close to the left end of the receiving plate 15, the ring electromagnet 8 is powered off, the conical spring 9 extends upward to enlarge the opening, and the steel balls entering the conical spring 9 5 can smoothly fall into the launch tube 4 , which increases the probability of the steel ball 5 entering the launch tube 4 and ensures the recovery of the steel ball 5 .

The existence of the cylinder 10 can buffer the bearing plate 15 when it swings downward, and avoid that the bearing plate 15 moves too fast under the elastic force of the spring 2 and causes the steel ball 5 to fall off the bearing plate 15. At the same time, the bearing plate 15 carries the steel ball 5. When the ball 5 swings downward, the compressed air cylinder 10 generates compressed air. When the recovery of the steel ball 5 is completed, the compressed air in the air storage tank pushes the cylinder 10 to move. Under the action of the magnetic force of the iron 2 16 and the magnet block 1 17, the receiving plate 15 is brought into contact with the guide plate 14 again, which is ready for the next experiment.

As mentioned above, although one Embodiment of this invention was described, this invention is not limited to the said embodiment, Various changes are possible in the range which does not deviate from the summary of this invention.

Industrial Applicability

According to the present invention, the parabolic motion trajectory of the steel ball is collected by setting up a demonstration device and taking continuous pictures, then the pictures are analyzed and calculated by the computer, and the speed curve and motion trajectory are displayed on the display screen, so that the students form Intuitive understanding, and further analysis of the speed curve in a timely manner, deepened the understanding of the students and ensured the quality of teaching. By setting up a demonstration device and taking continuous pictures, the parabolic trajectory of the steel ball was collected, and then the pictures were collected through the computer. Analysis and calculation are carried out, and the speed curve and motion trajectory are displayed through the display screen, so that students can form an intuitive understanding, and further analyze the speed curve in time, which deepens the students' understanding and ensures the quality of teaching. The teaching optimization method is useful in the field of mathematics teaching.

Claims (4)

1. a university mathematics parabola demonstration teaching optimization method, is characterized in that: the method comprises the steps: S1: Put the demonstration device in front of the classroom blackboard, and place a mobile phone for image acquisition in front of the demonstration device; S2: After the completion of S1, show the students the parabolic trajectory of the steel ball at different launch angles through the demonstration device; S3: During the demonstration of the parabolic trajectory in S2, the moving position of the steel ball is collected by taking pictures continuously through the mobile phone, and the signal is sent to the computer, the speed of the steel ball at each position is calculated, and the speed curve is drawn; S4: Display the speed curve in S3 and the motion trajectory of the steel ball through the display screen; S5: The speed curve is decomposed on the display screen by the computer, and the horizontal motion speed and the vertical motion speed are calculated, so as to understand the essence of parabolic motion; Wherein, the demonstration device used in the method comprises a fixed plate (1), a connecting plate (2), a turntable (3), a launch tube (4), a controller and a computer, and the fixed plate (1) is placed vertically and fixed The bottom end of the plate (1) is provided with a groove (11) vertically upward, the groove (11) is located inside the fixing plate (1), the front end surface of the fixing plate (1) is evenly provided with through holes, and the through holes are connected with the fixing plate (1) The internal grooves (11) communicate with each other, and the through holes are provided with a magnetic switch (12) and an LED light (13); the magnetic switch (12) is electrically connected to a controller; the controller is connected to a computer; The connecting plate (2) is vertically arranged below the fixing plate (1); the turntable (3) is rotatably mounted on the connecting plate (2) through the first rotating shaft (31), and the turntable (3) can be mounted on the connecting plate (3). 2) in the vertical plane, the turntable (3) is located below the fixed plate (1); the launch tube (4) is rotated and installed on the turntable (3) through the second shaft (41), and the launch tube (4) is used for In order to throw the steel ball (5), a cylindrical sliding groove (42) is arranged along the middle position of the upper end face of the launching cylinder (4) along its own axis. The cylindrical sliding groove (42) stores the steel ball (5), and the launching cylinder (4) Located just below the groove (11) of the fixed plate (1), the diameter of the cylindrical sliding groove (42) of the launch cylinder (4) is the same as the width of the groove (11) of the fixed plate (1). (4) A launching unit (6) is provided inside, and the launching unit (6) is used to push out the steel ball (5) in the launching cylinder (4), so that the steel ball (5) is in the groove (11) of the fixing plate (1). ) in a parabolic trajectory, and during the movement of the steel ball (5) in the groove (11) of the fixed plate (1), the magnetic switch (12) in the through hole on the movement trajectory is triggered to make the LED light (13) ) lights up; the axis of the second rotating shaft (41) is horizontal, the second rotating shaft (41) is fixed on the upper end of the launch cylinder (4), and the axis of the second rotating shaft (41) is located at the horizontal plane where the open end face of the launch cylinder (4) is located within; in which, The launching unit (6) includes a push plate (61), a spring one, an electromagnet (62), a rotating plate (63), a worm (64) and a motor (65), and the push plate (61) is located in the launching tube. In the cylindrical sliding groove (42) of (4), the push plate (61) is made of ferromagnetic material; the spring is located inside the launch cylinder (4), and the spring is used to provide elastic force to make the push plate (61) along the The first electromagnet (62) is built into the bottom of the launch cylinder (4), and the first electromagnet (62) is used to make the push plate (61) move along the sliding groove (42) through the action of magnetic force ) moves downward; the rotating plate (63) is installed at the bottom end of the launching cylinder (4), the rotating plate (63) is arc-shaped, and the center of curvature of the rotating plate (63) is connected to the sliding groove on the upper end surface of the launching cylinder (4). (42) The center points of the outlet coincide, and the lower surface of the rotating plate (63) is provided with a toothed structure; the worm (64) is horizontally installed on the rotating plate (3), the worm (64) is located under the rotating plate (63), and the worm (64) is located below the rotating plate (63). (64) engages with the toothed structure of the rotating plate (63); the motor (65) is mounted on the turntable (3), the motor (65) is used to drive the worm (64) to rotate, and the motor (65) is connected to the controller electrical connection; The fixing plate (1) is provided with a guide plate (14) at the bottom of the groove (11), and a receiving plate (15) is horizontally arranged below the fixing plate (1); 4) On the right side of the guide plate (14), the upper surface of the guide plate (14) is inclined with a high left and a low right, and the guide plate (14) is vertically provided with a discharge hole (141) near the right end surface; ) is located on the right side of the launching tube (4), the right end of the receiving plate (15) is hinged on the connecting plate (2), the receiving plate (15) is in contact with the guide plate (14) when it is in a horizontal state, and the receiving plate (15) is in the outlet A sensor is arranged below the material hole (141), a second electromagnet (16) is arranged at a position close to the left end of the receiving plate (15), and a magnet block is arranged on the guide plate (14) at a position corresponding to the second electromagnet (16). One (17), a second spring is arranged below the receiving plate (15), one end of the second spring is connected with the lower surface of the receiving plate (15), and the other end of the second spring is connected with the connecting plate (2), and the second spring is used to make The bearing plate (15) swings downward, and the connection between the bearing plate (15) and the turntable (3) is realized by a connecting rod (18); one end of the connecting rod (18) is hinged on the bearing plate (15), and the connecting rod ( 18) The other end is hinged with the turntable (3); the connecting plate (2) is also provided with a limiting plate (19); the limiting plate (19) is used to limit the downward swinging angle of the receiving plate (15) ; A display screen (7) is arranged on the front end surface of the fixing plate (1); the display screen (7) is transparent, and the display screen (7) is electrically connected with the computer. 2 . The method for optimizing the demonstration and teaching of university mathematics parabola according to claim 1 , characterized in that: a second magnet block ( 43 ) is provided on the inner side of the upper end of the launch cylinder ( 4 ). 3 . 3. a kind of university mathematics parabola demonstration teaching optimization method according to claim 1, is characterized in that: the position close to the upper end of described launch tube (4) is provided with annular electromagnet (8), and the launch tube (4) is also sleeved There is a conical spring (9), the upper end of the conical spring (9) is large in size and the lower end is small in size, and the conical spring (9) is made of ferromagnetic material. 4. A method for teaching optimization of university mathematics parabola demonstration according to claim 1, characterized in that: a cylinder (10) is provided between the limit plate (19) and the receiving plate (15); 10) Both ends are hinged on the limiting plate (19) and the receiving plate (15) respectively; the air cylinder (10) is connected with the air storage tank through the air pipe.

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