CN210515843U - A Coulomb Force Tester Based on Lightweight Lever - Google Patents

Abstract

The utility model provides a coulomb force experiment instrument based on a light lever, which is provided with a pendulum ball and a hollow conductor ball, wherein the two balls are connected with the same pole of a high-voltage direct-current power supply, and the pendulum ball can deviate from the vertical direction under the action of repulsion force of a coulomb; the position of the sliding seat is controlled to be unchanged, the output voltage of the high-voltage direct-current power supply is adjusted, and the change of the deflection angle of the swing ball is observed, so that the qualitative relation between the coulomb force and the charge quantity can be explored; adjusting the displacement frame, changing the position of the pendulum ball, ensuring that the center of the pendulum ball and the center of the hollow conductor ball are positioned on a line calibrated by the coulomb force experiment instrument, and measuring the distance r between the two centers of the pendulum ball and the distance h between the suspension point of the sliding seat and the line calibrated by the coulomb force experiment instrument by combining a reading system, thereby indirectly measuring the coulomb force F; similarly, the quantitative relation between the coulomb force F and the distance r between two sphere centers can be explored by changing the output voltage of the high-voltage direct-current power supply and measuring a plurality of groups of F and r.

Description

A Coulomb Force Tester Based on Lightweight Lever

technical field

The utility model relates to the technical field of teaching instruments, in particular to a Coulomb force experiment instrument based on a lightweight lever, which is used to demonstrate and explore which factors are related to the Coulomb force in teaching.

Background technique

The experimental instrument used in the current teaching to demonstrate and explore the factors affecting the interaction force between charges is shown in Figure 1. The main components involved in this experiment include: spherical conductor О and electrostatic pendulum, and the influencing factors naturally come from these two. The influencing factors are mainly analyzed from the following four aspects: one is to analyze the charge and leakage of the spherical conductor О and the pendulum ball; the second is to analyze the influence of the mass and volume of the electrostatic pendulum on its swing; the third is to analyze the pendulum ball and the spherical How to determine the distance r between conductors О; the fourth is to analyze how to choose the suspension wire. Through analysis, it can be found that the experiment shown in Figure 1 has the following problems or deficiencies:

1. It is greatly affected by the experimental environment, and it is necessary to ensure that the environment is dry. Due to the pendulum ball and the spherical conductor О, in a humid environment, the discharge electrode is fast, which leads to inconspicuous experimental phenomena, and even there is no way to make experimental phenomena, which limits the time and place of teaching and affects normal teaching.

2. Only the qualitative relationship between the interaction force and distance between charges can be explored, and the quantitative relationship between the interaction force and distance between charges cannot be explored. It is difficult to highlight and break through the key points and difficulties of the teaching content in this section.

3. The maintenance of the electric charge of the spherical conductor О and the pendulum ball. If the spherical conductor О and the pendulum ball are both used as capacitors, according to the discharge law of the RC circuit, the change of the electric charge on the spherical conductor О and the pendulum ball is expressed as follows:

The spherical conductor О has a very fast discharge speed. If the bottom is supported by a wooden stick, the discharge time is only about 4s. The charging time of the spherical conductor О is extremely short, and it is not easy to see the experimental phenomenon.

4. The pendulum ball is small in size, carries a small amount of electric charge, and has a faster discharge time, which also makes it difficult to obtain experimental phenomena or the time for experimental phenomena to appear is extremely short, which brings a lot of inconvenience to teaching.

5. The center of the pendulum ball and the spherical conductor О are not always at the same height. Initially, the center of the pendulum ball and the spherical conductor О are the same height, on the same horizontal line, but when the pendulum ball deviates from the vertical direction by a certain angle, the center of the pendulum ball and the spherical conductor О are no longer the same height. When analyzing the force of the pendulum ball, the interaction force between the electric charges and the gravity of the pendulum ball are no longer perpendicular to each other, and the interaction force between the electric charges on the pendulum ball cannot be expressed by F=mg tanθ, which brings a lot of inconvenience. .

6. The electrostatic pendulum is not easy to stabilize after swinging. When the pendulum ball is suspended by a thin wire, when the pendulum ball is subjected to Coulomb force and deviates from a certain angle from the vertical direction, it cannot be stopped quickly, and it will vibrate near a certain position for a long time, which is not conducive to classroom teaching.

To sum up, there are many deficiencies in the experimental device used to demonstrate the Coulomb force in the current high school physics teaching as shown in Figure 1, so it is necessary to improve it.

Utility model content

In order to overcome the technical defects in the experiment shown in FIG. 1, the present utility model proposes a Coulomb force tester based on a light-weight lever, which includes a main box, a sliding seat, an electrostatic pendulum, a shift frame, a hollow conductor ball and a reading system ; The sliding seat, the electrostatic pendulum, the displacement frame and the hollow conductor ball are all arranged in the main box body, the reading system is arranged on the outer wall of the main box body, and the sliding seat is arranged in the On the displacement frame, the electrostatic pendulum is arranged on the sliding seat, and the hollow conductor ball is arranged under the displacement frame; the hollow conductor ball is supported by the insulating support rod.

In the utility model, the main box body includes: a box cover, a traction rope winding wheel, a traction rope through hole, a pendulum ball connection post, a rack limit slot, a horizontal slide rail through hole, a fixed ruler placement rack and a power supply connection post ; The traction rope winding wheel and the traction rope through hole are arranged on the outside of the main box body, and the axes of the two are located on the same horizontal plane; the traction rope through hole is used for the traction rope to pass from the main box body. The inner side wall of the cable is passed through and wound on the traction rope winding wheel; the pendulum ball terminal and the power terminal are used to connect with the high-voltage DC power supply, so as to ensure that the pendulum ball and the hollow conductor ball have the same The rack limit slot is arranged on the inner side of the main box for placing the vertical movable rack; the transmission rod through holes are arranged on both sides of the main box, with It is used to set the transmission rod; the fixed ruler placing rack is arranged on the outer side of the bottom of the main box, and is used for placing the fixed ruler.

In the utility model, the sliding seat comprises: a traction rope, a damping groove, a horizontal sliding rail through hole, a V-shaped conductive suspension rod and a sliding seat terminal; the traction rope is used for pulling the sliding seat on the horizontal sliding rail move left and right; the damping slot and the damping sheet are used in combination, so that the electrostatic pendulum can be quickly stopped in the case of swinging; the horizontal slide rail through hole is used for the horizontal slide rail to pass through the sliding seat; so The V-shaped conductive suspension rod is used for suspending the electrostatic pendulum, and is connected with the sliding seat terminal, so that the pendulum ball can be charged.

In the utility model, the electrostatic pendulum includes: a counterweight, an M-shaped conductive suspension rod, a pendulum rod, a pendulum ball and a damping sheet; the counterweight is arranged on the top of the electrostatic pendulum, so that the electrostatic pendulum can remove the The center of gravity of the remaining part outside the pendulum ball is on the connecting line of the two suspension points of the M-type conductive suspension rod, so that the Coulomb force on the pendulum ball is easily measured; the pendulum rod includes a wire conductor for passing the wire. hole to ensure the pendulum ball is charged.

In the utility model, the shift frame includes: a horizontal slide rail, a connecting block, a vertical movable rack, a gear, a transmission rod and a hand wheel; the connecting block connects the horizontal slide rail and the vertical movable rack. The movable rack is fixed to be vertical to ensure that the sliding seat can move freely in a two-dimensional plane;

In the utility model, the hollow conductor ball includes: an insulating support rod; the insulating support rod is used to support the hollow conductor ball and play an insulating role.

In the utility model, the reading system includes: a vertical laser rangefinder, a vertical rangefinder reflector, a data display screen, a horizontal rangefinder reflector frame, a fixed ruler, and a laser pointer; the vertical laser rangefinder It is arranged at the bottom of the main box and used in conjunction with the vertical ranging reflective sheet; the data display screen is arranged on the outside of the main box to display the measured data; the horizontal ranging The reflective sheet holder is arranged on the fixed ruler and can move left and right freely; the laser pointer is arranged on the horizontal ranging reflective sheet holder for determining the position of the pendulum ball.

In the present invention, the size of the rack limit slot matches the size of the vertical movable rack to ensure that the vertical movable rack can move up and down in the rack limit slot, Then the shifting frame can move in the vertical direction to change the position of the pendulum ball in the vertical direction; the sliding seat is placed on the horizontal sliding rail through the The sliding seat can move left and right on the horizontal slide rail to change the position of the pendulum ball in the horizontal direction; the position of the pendulum ball in the two-dimensional plane can be changed by the action of the shift frame.

In the utility model, one end of the traction rope is arranged on the sliding seat, and the other end is arranged on the traction rope winding wheel, and the position of the sliding seat is changed by rotating the traction rope winding wheel;

In the present invention, the V-shaped conductive suspension rod is matched with the M-shaped conductive suspension rod to ensure that the electrostatic pendulum can swing freely in the vertical direction, and can ensure that the pendulum ball can be charged.

In the present invention, the connecting block further comprises: a vertical ranging reflective sheet support rod; the vertical ranging reflective sheet supporting rod is arranged above the connecting block and used to support the vertical ranging reflective sheet The reflective surface of the vertical distance measuring reflective sheet is flush with the suspension point of the M-type conductive suspension rod; and the upper surface of the vertical laser rangefinder and the center of the hollow conductor ball are in the same position On the same horizontal plane, the vertical height can be measured;

In the utility model, the horizontal ranging reflective sheet holder further comprises: a fixed ruler through hole and a laser pointer placement hole; the fixed ruler through hole is used for the fixed ruler to pass through, and the horizontal ranging reflective sheet holder is It is placed on the through hole of the fixed ruler, and ensures that the horizontal ranging reflector frame can move freely left and right; the laser pointer placement hole is used to place the laser pointer; the laser pointer's light spot and the hollow conductor are The center of the ball is on the same horizontal plane; by moving the position of the horizontal ranging reflector frame, the light spot of the laser pointer is irradiated on the position corresponding to the center of the pendulum ball, that is, to ensure that the pendulum ball The center of the hollow conductor sphere is on the same horizontal plane, and the distance between the two sphere centers can be read through the data display screen.

The utility model is easy to operate, the phenomenon is intuitive and obvious, the data is easy to measure, the classroom time is effectively saved, and the classroom efficiency is improved; the two balls are constantly connected with the power supply through the wire, which reduces the influence of the external environment on the experiment, and is easy to carry out quantitative experiments. The difficulties in this experimental teaching have broad application prospects.

Description of drawings

FIG. 1 is a schematic diagram of an experimental apparatus in the prior art for exploring factors affecting the interaction force between charges.

FIG. 2 is a schematic structural diagram of a Coulomb force tester based on a lightweight lever of the present invention.

FIG. 3 is a top view of the Coulomb force tester based on the lightweight lever of the present invention.

FIG. 4 is a front view of the Coulomb force tester based on the light-weight lever of the present invention.

Fig. 5 is the left side view of the Coulomb force tester based on the lightweight lever of the present invention.

FIG. 6 is a schematic structural diagram of the main box in the present invention.

FIG. 7 is a top view of the main box in the utility model.

Fig. 8 is the front view of the main box in the utility model

FIG. 9 is a left side view of the main box in the utility model.

FIG. 10 is a schematic structural diagram of a sliding seat in the present invention.

FIG. 11 is a top view of the sliding seat in the present invention.

Figure 12 is a front view of the sliding seat in the utility model.

13 is a schematic structural diagram of an electrostatic pendulum in the present invention.

14 is a top view of the electrostatic pendulum in the present invention.

FIG. 15 is a front view of the electrostatic pendulum in the utility model.

Figure 16 is a left side view of the electrostatic pendulum in the utility model.

FIG. 17 is a schematic structural diagram of the shift frame in the present invention.

FIG. 18 is a top view of the shift frame in the present invention.

Fig. 19 is a front view of the shift frame in the utility model.

Figure 20 is a left side view of the shift frame in the present invention.

FIG. 21 is a schematic structural diagram of the hollow conductor ball of the present invention.

FIG. 22 is a schematic structural diagram of the horizontal ranging reflector frame and the laser pointer in the present invention.

23 is a top view of the horizontal ranging reflector frame and the laser pointer in the present invention.

FIG. 24 is a front view of the horizontal ranging reflector frame and the laser pointer in the present invention.

Figure 25 is the left side view of the horizontal ranging reflector frame and the laser pointer in the present invention.

FIG. 26 is a schematic diagram of processing by the image method in the present invention.

Detailed ways

The utility model will be further described in detail with reference to the following specific embodiments and accompanying drawings. Except for the contents specifically mentioned below, the process, conditions, experimental methods, etc. for implementing the present invention are all common knowledge and common knowledge in the field, and the present invention has no special limited contents.

As shown in Figures 1 to 25, the present utility model proposes a light-weight lever-based Coulomb force experimenter, comprising: a main box, a sliding seat, an electrostatic pendulum, a shift frame, a hollow conductor ball and a reading system; The sliding seat, the electrostatic pendulum, the shifting frame and the hollow conductor ball are all arranged in the main box, the reading system is arranged on the outer wall of the main box, the sliding seat is arranged on the shifting frame, the electrostatic pendulum is arranged on the sliding seat, and the hollow The conductor ball is arranged below the shift frame.

The main box body includes: a box cover, a traction rope winding wheel, a traction rope through hole, a pendulum ball terminal, a rack limit slot, a transmission rod through hole, a fixed ruler placement rack and a power supply terminal; among them,

The traction rope winding wheel and the traction rope through hole are arranged on the outer side of the top of the main box, and the axes of the two are on the same horizontal plane; the traction rope through hole is used for the traction rope to pass through the inner side wall of the main box and wrap around the traction rope On the winding wheel; one end of the traction rope is set on the sliding seat, and the other end is set on the traction rope winding wheel, and the sliding seat can be pulled by rotating the traction rope winding wheel; a traction rope is set on each side of the main box If the winding wheel is used, the two traction rope winding wheels can be rotated respectively to pull the sliding seat to move in the left and right directions; With the same charge; the rack limit slot is arranged on the inner side of the bottom of the main box for placing the vertical movable rack; the two rack limit slots are symmetrically arranged at both ends of the main box, and are located in On the respective symmetrical axes of the two ends; the size of the rack limit slot matches the size of the vertical movable rack to ensure that the vertical movable rack can move up and down freely in the rack limit slot, and accordingly, The shift frame can move freely in the vertical direction to change the position of the pendulum ball in the vertical direction; the sliding seat is placed on the horizontal sliding rail through the through hole of the horizontal sliding rail to ensure that the sliding seat can move left and right on the horizontal sliding rail, Change the position of the pendulum ball in the horizontal direction; then through the action of the shift frame, the position of the pendulum ball in the two-dimensional plane can be changed. The through holes of the transmission rod are arranged on both sides of the main box for setting the transmission rod; the fixed ruler placement rack is arranged on the outer side of the bottom of the main box for placing the fixed ruler;

The sliding seat includes: traction rope, damping groove, horizontal sliding rail through hole, V-shaped conductive suspension rod, sliding seat binding post; among them,

The traction rope is used to pull the sliding seat to move left and right on the horizontal slide rail; one end of the traction rope is set on the sliding seat, and the other end is set on the traction rope winding wheel, and the position of the sliding seat can be changed by rotating the traction rope winding wheel. The combination of damping groove and damping sheet can quickly stop the swinging electrostatic pendulum; the through hole of the horizontal slide rail is used for the horizontal slide rail to pass through the sliding seat; the V-shaped conductive suspension rod is used to suspend the electrostatic pendulum, and is combined with the sliding seat binding post , to ensure that the electrostatic pendulum can swing freely in the vertical direction, and to ensure that the pendulum ball is charged;

The electrostatic pendulum includes: counterweight, M-type conductive suspension rod, pendulum rod, pendulum ball and damping sheet; among them,

The counterweight is set on the top of the electrostatic pendulum, so that the center of gravity of the electrostatic pendulum without the pendulum ball is on the connection line between the two suspension points of the M-type conductive suspension rod, which is convenient to measure the Coulomb force on the pendulum ball; In the static state, the Coulomb force of the pendulum ball subjected to the hollow conductor ball can be calculated;

The pendulum rod further includes: a wire through hole; the wire through hole is used for the wire to pass through, and the wire connects the M-type conductive suspension rod and the pendulum ball to ensure that the pendulum ball can be charged;

The shift frame is in the shape of "n", and the shift frame includes: horizontal slide rail, connecting block, vertical movable rack, gear, transmission rod, hand wheel; among them,

The connecting block fixes the horizontal slide rail and the vertical movable rack to "┌". The two connecting blocks are located at both ends of the horizontal slide rail, and fix the vertical movable racks at both ends together, so that the shift frame It is in the shape of "n"; the vertical movable rack is coupled with the gear, and the position of the vertical movable rack in the limit slot of the rack can be changed by rotating the gear, that is, the vertical movable rack can be moved in the vertical direction. Move up and down; the transmission rod vertically passes through the main box body through the transmission rod through hole, and both ends are located outside the main box body; the gear is set on the transmission rod, and the handwheel is set on both ends of the transmission rod; The vertical position of the shift frame can be changed; the sliding seat is located on the horizontal slide rail, the vertical position of the sliding seat can be changed by turning the handwheel, and the vertical position of the sliding seat can be changed by turning the traction rope winding wheel. When the sliding seat is in the horizontal direction, the pendulum ball can move freely in the two-dimensional plane;

The connecting block further includes: a vertical ranging reflective sheet support rod; the vertical ranging reflective sheet supporting rod is arranged above the connecting block and used to support the vertical ranging reflective sheet; The suspension points of the conductive suspension rod are flush with each other; and the upper surface of the vertical laser rangefinder and the center of the hollow conductor ball are on the same horizontal plane, the vertical height h can be measured;

The hollow conductor ball includes: an insulating support rod; the insulating support rod is used to support the hollow conductor ball to keep it in an insulating state;

The reading system includes: a vertical laser rangefinder, a vertical rangefinder reflector, a data display screen, a horizontal rangefinder reflector frame, a fixed ruler, and a laser pointer; among them,

The vertical laser rangefinder is set at the bottom of the main box and used together with the vertical range-finder reflector; the data display screen is set on the outside of the main box to display the measured data; the horizontal range-finder reflector frame is set On a fixed ruler, and can move left and right freely; the laser pointer is set on the horizontal ranging reflector frame to determine the position of the pendulum ball;

The horizontal ranging reflector frame further includes: a fixed ruler through hole and a laser pointer placement hole; the fixed ruler through hole is used for the fixed ruler to pass through, and the horizontal ranging reflector frame is placed on the fixed ruler through hole, and the horizontal ranging is guaranteed. The reflector holder can move freely left and right; the laser pointer placement hole is used to place the laser pointer; the laser pointer’s light spot and the center of the hollow conductor ball are on the same level; by moving the position of the horizontal ranging reflector holder, the laser pointer’s light spot Irradiate on the position corresponding to the center of the pendulum ball, that is, ensure that the center of the pendulum ball and the hollow conductor ball are on the same level, and the distance r between the two centers can be read through the data display screen;

即

利用图像法对F和r进行数据处理，即可得出两者的关系。According to the design principle of this Coulomb force tester, when the suspended pendulum ball is affected by the Coulomb force and deviates from the vertical direction by a certain angle θ, it is in a state of equilibrium, and the center of the pendulum ball and the center of the hollow conductor ball are at the same height. , on the same horizontal plane calibrated by the Coulomb force tester, and analyzing the force of the pendulum ball, it can be known that F=mg tanθ; if the pendulum length of the electrostatic pendulum is L, according to the geometric relationship,

which is

Using the image method to process the data of F and r, the relationship between the two can be obtained.

The utility model is provided with a pendulum ball and a hollow conductor ball, both of which are connected to the same pole of a high-voltage direct current power supply, and the pendulum ball will deviate from the vertical direction under the action of Coulomb repulsion; the position of the control sliding seat remains unchanged, and the high-voltage direct current is adjusted. The output voltage of the power supply and the change of the declination angle of the pendulum ball can be observed to explore the qualitative relationship between the Coulomb force and the amount of charge; then adjust the shift frame to change the position of the pendulum ball and ensure that the center of the ball and the center of the hollow conductor ball are in the same position. The Coulomb force F can be measured on the same horizontal plane calibrated by the Coulomb force tester and combined with the reading system to measure the distance r between the two spherical centers and the distance h between the suspension point of the sliding seat and the straight line calibrated by the Coulomb force tester; Similarly, by changing the output voltage of the high-voltage DC power supply and measuring multiple groups of F and r, the quantitative relationship between the Coulomb force F and the distance r between the centers of the two spheres can be explored.

Example

Coulomb force tester in this embodiment:

1. Main box

Main box: length 50cm, width 10cm, height 30cm, thickness 0.5cm;

Box cover: length 50cm, width 10cm, thickness 0.5cm;

Traction rope winding wheel: in the shape of "I"; the diameter of the outer wheel is 3cm, the diameter of the inner wheel is 1cm, and the length is 2cm;

Traction rope through hole: hole diameter 0.4cm;

Pendulum ball binding post: "I" shape; 3cm long, 1cm outer diameter;

Rack limit slot: "concave" shape, length 12cm, outer width 3cm, inner width 2cm;

Transmission rod through hole: hole diameter 1cm; one transmission rod through hole on each side of the main box;

Fixed ruler placement rack: length 2.5cm, width 2cm, height 5cm, thickness 0.2cm;

Power supply terminal: "I" shape; 3cm long, 1cm outer diameter;

Second, the sliding seat

Sliding seat: length 10cm, width 5cm, height 3cm, thickness 0.3cm;

Traction rope: 60cm long, there are two; located on both sides of the sliding seat, used to change the position of the sliding seat;

Damping tank: length 2cm, width 1cm, depth 2cm; in the damping tank, add liquid with high viscosity coefficient, such as castor oil, etc.;

Horizontal slide rail through hole: The hole diameter is 0.4cm, and there are two horizontal slide rail through holes on both sides, which are used for two horizontal slide rails to pass through;

V-shaped conductive suspension rod: outer diameter 0.2cm, length 0.5cm

Sliding seat binding post: "I" shape; 3cm long, 1cm outer diameter;

3. Electrostatic pendulum

Counterweight: outer diameter 1cm, height 1cm;

M-type conductive suspension rod: outer diameter 0.2cm;

Swing rod: outer diameter 0.4cm, inner diameter 0.2cm, length 10cm;

Pendulum ball: diameter 1cm, weight 0.136g;

Damping sheet: square, side length 0.5cm, thickness 0.2cm;

Conductor through hole: aperture 0.2cm;

4. Shift rack

Shifting frame: length 49cm, width 4cm, height 12cm;

Horizontal rail: length 46cm, outer diameter 0.4cm;

Connection block: length 8cm, width 5cm, thickness 2cm;

Vertical movable rack: length 12cm, width 2cm, thickness 1cm;

Transmission gear: outer diameter 3cm, inner diameter 1cm, thickness 0.3cm;

Transmission rod: length 56cm, outer diameter 1cm;

Handwheel: outer diameter 5cm, inner diameter 1cm;

5. Hollow conductor ball

Hollow conductor ball: outer diameter 10cm;

Insulation support rod: outer diameter 0.6cm, length 5cm;

6. Reading system

Vertical laser rangefinder: length 5cm, width 2cm, height 10cm;

Vertical ranging reflector: length 5cm, width 5cm, thickness 0.3cm; aperture 0.4cm;

Data display: length 10cm, width 5cm, thickness 3cm;

Horizontal ranging reflector frame: length 5cm, width 5cm;

Fixed ruler: length 38cm, width 4cm, thickness 0.4cm;

Laser pointer: length 10cm, outer diameter 2cm;

Experimental operation essentials

【Experiment 1】Explore the relationship between the interaction force between charges and the amount of charge:

Steps:

1. Connect the high-voltage DC power supply to the hollow conductor ball and the pendulum ball with wires.

2. Adjust the sliding seat so that the hollow conductor ball and the pendulum ball are separated by a certain distance.

3. Turn on the voltage DC power switch and observe the experimental phenomenon.

4. Keep the position of the sliding seat unchanged, change the voltage value several times, repeat the above experimental steps, observe and record the experimental phenomenon.

5. Analyze experimental phenomena and draw experimental conclusions.

[Experiment 2] Explore the relationship between the interaction force and distance between charges:

Steps:

1. Connect the high-voltage DC power supply to the hollow conductor ball and the pendulum ball with wires, and turn on the laser pointer switch.

2. Adjust the horizontal shift frame so that the pendulum ball of the electrostatic pendulum is at a certain distance from the hollow conductor ball.

3. Turn on the high-voltage DC power switch and adjust the voltage until the pendulum ball is bounced. In order to make the experimental phenomenon more obvious, you can continue to increase the voltage until the declination angle of the pendulum ball is large enough.

4. Quickly move the vertical shift frame and the laser marking reading board, so that the light spot of the laser pointer hits the horizontal plane corresponding to the center of the pendulum ball, and read the distance r between the two centers and the electrostatic pendulum suspension. Point the height h from the center of the pendulum ball and record it.

5. Keep the voltage unchanged, move the electrostatic pendulum to the right, and change the distance r between the pendulum ball and the hollow conductor ball several times (reduce).

6. Repeat the above steps several times to record multiple sets of r and h.

7. Carry out data processing, analyze and draw experimental conclusions.

Data recording and processing:

Data processing:

Analyze the data to find the relationship between F and r. Since the mass of the pendulum ball is unchanged and the geographical position of the pendulum is unchanged, the gravity of the pendulum ball is unchanged. According to F=mg tanθ, F is proportional to tanθ, The image method is used for processing, as shown in Figure 26:

Error Analysis:

图像中，添加了趋势线，得到趋势线的表达式为y＝0.066x-0.0107，并不过原点，不成正比，误差可能来源：

In the image, a trend line is added, and the expression of the trend line is y=0.066x-0.0107, which is not the origin and is not proportional. The error may come from:

1. The hollow conductor ball and the pendulum ball are connected to the high-voltage DC power supply. The voltage of the high-voltage DC power supply is unstable and fluctuates back and forth, causing the charge on the hollow conductor ball and the pendulum ball to change.

2. The position of the center of the pendulum ball and the hollow conductor ball is not determined accurately.

3. Affected by the experimental environment.

Experimental results:

图像中，添加了趋势线，得到趋势线的表达式为y＝0.066x-0.0107，其中截距为0.0107很小，可以忽略不计，得到的关系式为

即在误差允许的范围内，电荷间的相互作用力与空心导体球和摆球的距离的平方的倒数成正比。

In the image, a trend line is added, and the expression of the trend line is y=0.066x-0.0107, where the intercept is 0.0107, which is very small and can be ignored, and the obtained relationship is

That is, within the allowable range of error, the interaction force between charges is proportional to the inverse of the square of the distance between the hollow conductor ball and the pendulum ball.

The protection content of the present invention is not limited to the above embodiments. Without departing from the spirit and scope of the concept of the utility model, the changes and advantages that can be conceived by those skilled in the art are all included in the present utility model, and the appended claims are the protection scope.

Claims (6)

1. A coulomb force experiment instrument based on a light lever is characterized by comprising a main box body (1), a sliding seat (2), an electrostatic pendulum (3), a displacement frame (4), a hollow conductor ball (5) and a reading system; the sliding seat (2), the electrostatic pendulum (3), the shifting frame (4) and the hollow conductor ball (5) are all arranged in the main box body (1), the reading system is arranged on the outer wall of the main box body (1), the sliding seat (2) is arranged on the shifting frame (4), the electrostatic pendulum (3) is arranged on the sliding seat (2), and the hollow conductor ball (5) is arranged below the shifting frame (4); wherein,

the main box body (1) includes: the device comprises a box cover (11), a traction rope winding wheel (12), a traction rope through hole (13), a pendulum ball binding post (14), a rack limiting groove (15), a transmission rod through hole (16), a fixed ruler placing frame (17) and a power supply binding post (18); the traction rope winding wheel (12) and the traction rope through hole (13) are arranged on the outer side of the main box body (1), and the axes of the traction rope winding wheel and the traction rope through hole are positioned on the same horizontal plane; the traction rope through hole (13) is used for a traction rope (21) to penetrate out of the inner side wall of the main box body (1) and to be wound on the traction rope winding wheel (12); the swing ball binding post (14) and the power supply binding post (18) are used for being connected with a direct current power supply, so that the swing ball (34) and the hollow conductor ball (5) are ensured to be charged in the same way; the rack limiting groove (15) is arranged on the inner side wall of the main box body (1) and is used for placing a vertical movable rack (43); the transmission rod through holes (16) are arranged on two sides of the main box body (1) and used for arranging transmission rods (45); the fixed ruler placing frame (17) is arranged on the outer side of the bottom of the main box body (1) and used for placing a fixed ruler (65);

the sliding seat (2) comprises: the device comprises a traction rope (21), a damping groove (22), a horizontal sliding rail through hole (23), a V-shaped conductive suspension rod (24) and a sliding seat binding post (25); the traction rope (21) is used for drawing the sliding seat (2) to move left and right on the horizontal sliding rail (41); the damping groove (22) and the damping sheet (35) are used in combination, so that the static pendulum (3) can be rapidly stopped under the condition of swinging; the horizontal sliding rail through hole (23) is used for enabling the horizontal sliding rail (41) to penetrate through the sliding seat (2); the V-shaped conductive suspension rod (24) is used for suspending the electrostatic pendulum (3) and is combined with the sliding seat binding post (25) to electrify the electrostatic pendulum (3);

the electrostatic pendulum (3) comprises: the device comprises a counterweight (31), an M-shaped conductive suspension rod (32), a swing rod (33), a swing ball (34) and a damping fin (35); the balance weight (31) is arranged at the top of the static pendulum (3), so that the center of gravity of the rest part of the static pendulum (3) except the pendulum ball (34) is positioned on the connecting line of the two suspension points of the M-shaped conductive suspension rod (32), and the coulomb force borne by the pendulum ball (34) can be conveniently measured; the swing rod (33) comprises a lead through hole (331) for leading a lead to pass through, and the swing ball (34) is ensured to be electrified;

the displacement carriage (4) comprises: the device comprises a horizontal sliding rail (41), a connecting block (42), a vertical movable rack (43), a gear (44), a transmission rod (45) and a hand wheel (46); the joint block (42) fixedly connects the horizontal sliding rail (41) and the vertically movable rack (43) together and enables the horizontal sliding rail and the vertically movable rack to be perpendicular to each other, so that the sliding seat (2) can move freely in a two-dimensional plane;

the hollow conductor ball (5) comprises: an insulating support rod (51); the insulating support rod (51) is used for supporting the hollow conductor ball (5) and ensuring insulation;

the reading system comprises: the device comprises a vertical laser range finder (61), a vertical range finding reflector (62), a data display screen (63), a horizontal range finding reflector frame (64), a fixed ruler (65) and a laser pen (66); the vertical laser range finder (61) is arranged at the bottom of the main box body (1) and is matched with the vertical range finding reflector (62) for use; the data display screen (63) is arranged on the outer side of the main box body (1) and used for displaying measured data; the horizontal distance measurement reflector frame (64) is arranged on the fixed ruler (65) and can move left and right along the fixed ruler (65); the laser pen (66) is arranged on the horizontal ranging reflector frame (64) and used for determining the position of the pendulum ball (34).

2. The coulomb force experiment instrument based on light weight levers as claimed in claim 1, characterized in that the size of the rack limiting groove (15) matches with the size of the vertically movable rack (43), ensuring that the vertically movable rack (43) can move up and down in the rack limiting groove (15), then the displacement frame (4) can move in the vertical direction, changing the position of the pendulum ball (34) in the vertical direction; the sliding seat (2) is placed on the horizontal sliding rail (41) through the horizontal sliding rail through hole (23), so that the sliding seat (2) can move left and right on the horizontal sliding rail (41) to change the position of the swinging ball (34) in the horizontal direction; the position of the pendulum ball (34) in a two-dimensional plane can be changed by the action of the displacement frame (4).

3. The coulomb force test instrument based on light weight levers as claimed in claim 1, characterized in that one end of the traction rope (21) is arranged on the sliding seat (2) and the other end is arranged on the traction rope winding wheel (12), the position of the sliding seat (2) is changed by rotating the traction rope winding wheel (12).

4. The coulomb force experiment instrument based on light weight levers as claimed in claim 1, characterized in that the V-shaped conductive suspension rod (24) is matched with the M-shaped conductive suspension rod (32), ensuring that the static pendulum (3) can swing freely in vertical direction and ensuring that the pendulum ball (34) is charged.

5. The lightweight lever-based coulomb force tester of claim 1 wherein the adapter block (42) further comprises: a vertical ranging reflective sheet support bar (421); the vertical distance measurement reflecting sheet supporting rod (421) is arranged above the connecting block (42) and is used for supporting the vertical distance measurement reflecting sheet (62); the reflecting surface of the vertical distance measurement reflecting sheet (62) is flush with the suspension point of the M-shaped conductive suspension rod (32); and the upper surface of the vertical laser range finder (61) and the center of the hollow conductor ball (5) are positioned on the same horizontal plane, so that the distance from the suspension point of the pendulum ball (34) to the center of the pendulum ball in the vertical direction can be measured.

6. The lightweight lever-based coulomb force tester as recited in claim 1, wherein said horizontal range reflector shelf (64) further comprises: a fixed ruler through hole (641) and a laser pen placing hole (642); the fixed ruler through hole (641) is used for the fixed ruler (65) to pass through, the horizontal ranging reflector frame (64) is placed on the fixed ruler through hole (641), and the horizontal ranging reflector frame (64) can move freely left and right; the laser pen placing hole (642) is used for placing the laser pen (66); the light spot of the laser pen (66) and the sphere center of the hollow conductor sphere (5) are always positioned on the same horizontal plane calibrated by the coulomb force experiment instrument; by moving the position of the horizontal ranging reflector frame (64), light spots of the laser pen (66) are irradiated on the position corresponding to the sphere center of the pendulum ball (34), namely, the sphere centers of the pendulum ball (34) and the hollow conductor ball (5) are ensured to be on the same horizontal plane calibrated by the coulomb force experiment instrument, and the distance between the two sphere centers can be read through the data display screen (63).

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