Q. A .450 kg ice puck, moving east with a speed of 3m/s, has a head-n collision with a .900 kg puck initially at rest. Assume a completely elastic collision, what will be the speed and direction of each object after collision?
Q. A light year is the unit of distance that light, with a speed of 2.99792e8 m/s, travels in one year. What is the surface area of the planet whose radius is 1300 km? Reply in units of lightyears^2.