Description

This program simulates the movement of a small ball on the block and a vertical pop-up after sliding on the block for one second.It is assumed that the internal force of the system does not change when the ball is ejected and does not affect the system.

Question: Will the ball return to the block after it leaves the block?

The simulation conditions are set: the mass of the block is 1 kg, the mass of the ball is 0.01 kg, the mass of the pull block is 1 kg, and the gravitational constant is 9.8 m / s^2.

The simulation is divided into two situations:

(a) "Cart travels at constant velocity": The pulley initially taxis at a constant speed of vx = 40 meters / second. The ball pops up on the ground at a speed of vy = 35 meters / second after sliding for one second. The red arrows respectively represent the speed of the ball in the x and y directions. The green arrow indicates the speed of the cart in the x direction.

(b) "Cart accelerates": The pulley is accelerated at a speed of vx = 40m / s by a heavy object, and the ball is vertical to the ground after one second of gliding. The speed is vy = 35m / s.

Display

Red arrow: ball speed vxa vs vya

Green arrow: cart speed

Red dots: the position of the ball every one second interval

Black dots: the position of the cart every one second interval

Simulation operation

Play pause button

Cart travels at constant velocity

Cart accelerates

Trace: Show the position of the pulley and the ball every second.

(1) Selecting mode

Press the button "Cart travels at constant velocity" or "Cart accelerates" to select the conditions to be observed.

(2) Executing the simulation

After resetting, press Reset to re-select the simulation conditions for the next simulation execution.

(3) Showing the position of the one-second interval between the block and the ball

Press the "Trace" button before pressing Play to run the simulation.

Students can discuss the movement of the projectile by observing the changes in the speed of the ball and the cart in the two situations. Students can also plot the time and displacement of the ball or the cart, time and speed, and discuss the movement behavior of the two.