Final answer:
The conservation laws of energy, momentum, and kinetic energy are used to determine pre-collision and post-collision velocities of two balls, as well as their maximum heights after an elastic collision.
Step-by-step explanation:
The student has asked about the velocities of two balls before and after an elastic collision and the maximum height they reach after the collision. Assuming no air resistance, the conservation of energy principle can be used to find the initial velocity of the lighter ball by equating potential energy at 60° to kinetic energy at the point just before impact.
Afterward, the conservation of momentum and kinetic energy can be used to determine the velocities of both balls post-collision. The final velocities can then be used with the conservation of energy again to find the maximum height each ball reaches after the elastic collision.
It's important to remember that, for an elastic collision, both conservation of momentum and conservation of kinetic energy hold true. So, the total kinetic energy before and after the collision remains constant, as well as the total momentum of the system. Applying these laws yields the final velocities for each mass, and subsequently, energy conservation can determine the maximum heights.