Activities

1. First, simply hit Play. With the default settings, the ball drops from rest from a height of 20 m, with a gravitational acceleration of 10 m/s/s directed down. Note how long the ball takes to reach the ground, and what the ball's velocity is when it hits the ground. Explain what the Motion Diagram shows.
2. Now, make a prediction. If you change the gravitational acceleration by a factor of 4, to 2.5 m/s/s, how long will the ball take to reach the ground now? What will the ball's velocity be when the ball hits the ground? Run the simulation with the new value of the gravitational acceleration to see if your predictions are correct.
3. Now, we'll change the settings so that the ball is launched up from ground level. First, predict what the graphs before you do this. Then, set the initial height to zero, and the initial velocity to +20 m/s, and see whether your predictions about the graphs are correct. Also, record the maximum height reached by the ball, and the time it spends in flight.
4. On the acceleration graph, does anything special happen when the ball reaches its highest point?
5. Predict what will happen when you change the initial velocity by a factor of 2, to +10 m/s instead of +20 m/s. Predict the new values of the maximum height and of the time-of-flight. Then, run the simulation with the new value of the initial velocity to see if your predictions are correct.