# Activities

1. Start with the initial values of all the sliders, and run the simulation by pressing the Play button. This is a relatively simple collision, a perfectly elastic collision between objects of equal mass. See if you can find the three momentum and the three kinetic energy values after the collision. Note that you can enter these one at a time, and use the "Check Answer" button to check each individual answer.
2. Reset the simulation (press the "Reset Simulation" button), and then set the mass of ball 1 to 3 kg, and the elasticity to 0. This gives what we call a completely inelastic collision, in which the objects stick together after the collision. See if you can predict the answers, for the momentum and kinetic energy afterwards, before running the simulation.
3. Reset the simulation again, and then set the mass of ball 1 to 3 kg. This should give you an elastic collision between objects with equal-and-opposite velocities before the collision, and a mass ratio of 3. This is a special case. See if you can predict the answers, for the momentum and kinetic energy afterwards, before running the simulation - make sure you Play it to see the result, though.
4. Adjust the sliders several times, running through various combinations of parameters. Under what conditions is the total momentum conserved in the collision? Under what conditions is the total kinetic energy conserved in the collision?
5. Finally, try a collision in which the elasticity is 0.5. Using the momentum conservation equation, and the elasticity equation, you should be able to solve for the momentum and kinetic energy after the collision. See if you can do this.