Summary of the invention
In view of this, the object of this invention is to provide a kind of experimental provision probing into demonstration theorem of momentum.
The object of the invention is to be achieved through the following technical solutions:
A kind of experimental provision probing into demonstration theorem of momentum, comprise base, support, collision weight, stilt and impulse force metering circuit, described support is fixed on base, described collision weight to hang on support and can swing back and forth, and described impulse force metering circuit collides for measuring and show the size that when weight and stilt collide, stilt is stressed.
Further, described collision weight is ball or right cylinder or square body.
Further, described collision weight and stilt are coated with dismountable soft layer.
Further, described experimental provision also comprises the index dial be fixed on support, and described index dial departs from the angle of equilibrium position for showing collision weight.
Further, described impulse force metering circuit comprises power supply, metallic resistance, impulse force meter, guide rail and sliding pin, described sliding pin is fixing on a support, above support horizontally slips along smooth guide, above support, power supply, impulse force meter, metallic resistance, sliding pin are sequentially connected in series, and collision weight changes the contact position of sliding pin and metallic resistance with this by the position changing stilt.
Further, described impulse force metering circuit also comprises the spring and metal link stopper that connect successively, and described metal link stopper to be fixed on base and to be connected with power supply, and described spring is connected with sliding pin.
Further, described impulse force metering circuit also comprises switch, and power supply is connected by switch with impulse force meter.
Further, described impulse force metering circuit also comprises current-limiting resistance, and impulse force meter is connected by current-limiting resistance with switch.
The invention has the beneficial effects as follows:
Structure of the present invention is simple, and draw materials easily, with low cost, simple to operate, successful, can help student to understand theorem of momentum intuitively, enrich the content of courses and teaching means.
Embodiment
Below in conjunction with accompanying drawing, the preferred embodiments of the present invention are described in detail.
As shown in the figure, a kind of experimental provision probing into demonstration theorem of momentum, comprise base 1, support 2, collision weight 4 stilt and impulse force metering circuit, described support 2 is fixed on base 1, described collision weight 4 hangs on support 2 and also can swing back and forth, and described impulse force metering circuit is for measuring and showing the size that when collision weight 4 collides with stilt, stilt is stressed.
Described collision weight 4 is ball or cylinder or square body, and the dismountable soft layer of one deck can be wrapped up in collision weight surface.
Described impulse force meter also comprises the index dial 5 be fixed on support 2, and described index dial 5 departs from the angle of equilibrium position for showing collision weight 4.
Described impulse force meter comprises power supply 12, metallic resistance 7, impulse force meter 3 and sliding pin 8, described sliding pin 8 is fixed on stilt 6, described power supply 12, impulse force meter 3, metallic resistance 7, sliding pin 8 and guide rail 14 are sequentially connected in series, sliding pin 8 is fixed on stilt 6, stilt 6 surface can be wrapped up the dismountable soft layer of one deck and also can be horizontally slipped on smooth guide, and collision weight 4 passes through to clash into the position changing stilt 6 changes sliding pin 8 and metallic resistance 7 contact position with this.
As the improvement to the present embodiment, described impulse force metering circuit also comprises the spring 9 and metal link stopper 11 that connect successively, and described metal link stopper 11 to be fixed on base 1 and to be connected with power supply 12, and described spring 9 is connected with sliding pin 8.Spring 9 can make the automatic correcting action of stilt.
Described impulse force metering circuit respectively also comprises switch 13, and power supply 12 is connected by switch 13 with impulse force meter 3.
Described impulse force metering circuit also comprises current-limiting resistance 10, and impulse force meter 3 is connected by current-limiting resistance 10 with switch 13.
When stilt 6 is not subject to impulse force, impulse force meter 3 registration is 0; When stilt 6 is subject to impulse force, the size of this impulse force just can be read from impulse force meter 3.Power is larger, and spring 9 decrement is larger, and the resistance value in metallic resistance 7 place in circuit reduces, and the registration of impulse force meter 3 just becomes large.So the size shown by impulse force meter just knows the size that stilt 6 is stressed.During experiment, after collision weight 4 is pulled open equilibrium position, freely discharge, transform gravitational energy is kinetic energy and collides in equilibrium position and stilt 6, the size of impulse force when demonstrating collision by impulse force meter 3.
The use step of this experimental provision:
1). when speed is constant, the relation of impulse force size and mass of object size when probing into collision
Closing Switch 13, makes collision weight 4 fall from sustained height (collision weight is pulled away from the identical angle in equilibrium position), namely ensures that speed is certain.Be inserted in by iron staff in collision thing or extract to change the quality of colliding weight, bumping against, can draw from the reading of impulse force dynamometer with collision weight 4 with stilt 6, when speed is constant, the quality of collision weight is larger, and during interaction, impulse force is larger.
2). during mass conservation, the relation of impulse force size and object speed size when probing into collision
Closing Switch 13, ensures collision weight mass conservation (do not insert iron staff or all insert iron staff), and collision weight is fallen from differing heights (weight being pulled away from the angle that equilibrium position is different), namely changes velocity magnitude during collision.Stilt bumps against with collision weight, and when can draw the mass conservation of object from the reading of impulse force dynamometer, speed is larger, and during interaction, impulse force is larger.
3). when quality, speed are constant, impulse force size and the relation of action time when probing into collision
Closing Switch 13, ensures collision weight mass conservation (do not insert iron staff or all insert iron staff), and collision weight is fallen from phase co-altitude (collision weight is pulled away from the identical angle in equilibrium position), and velocity magnitude when namely ensureing collision is identical.Collide (when first time collides with stilt and collision weight, collision weight or stilt surface superscribe soft layer, when second time is collided, soft layer is not wrapped up in collision weight and stilt surface), can draw from the reading of impulse force meter, when colliding weight package and wrapping soft layer, the interaction time is long, and impulse force is less; When colliding weight and not wrapping up soft layer, the interaction time is short, and impulse force is larger.
When collision weight quality and speed is all constant, illustrate that the initial momentum before its collision is identical, all vanishing of collision rift speed, illustrate that its last momentum is identical, then collision front and back momentum knots modification is identical.When colliding with different surfaces, action time is different, and the size of power is also different, illustrates that the knots modification of momentum is not the size decision of Dan Youli, but by power size and jointly determine action time, namely determined by momentum size.Quantitative relationship between the knots modification of object momentum and suffered momentum size is just showed by theorem of momentum.
The present invention also only can carry out the size of antistress according to the compression degree of the sliding distance of stilt on rough guide rail or spring.
What finally illustrate is, above preferred embodiment is only in order to illustrate technical scheme of the present invention and unrestricted, although by above preferred embodiment to invention has been detailed description, but those skilled in the art are to be understood that, various change can be made to it in the form and details, and not depart from claims of the present invention limited range.