Two identical iron balls each of mass 0.4 kg undergo an elastic collision. The first ball travels with a velocity of 4 m/s and the second ball is at rest. What is the momentum of the second
ball if the first ball comes to a stop after the collision?

During a medieval siege of a castle, the attacking army uses a trebuchet to hurl heavy stones at the castle walls. if the trebuchet launches the stones with a velocity of at an angle of 50.0°, (a) how long does it take the stone to hit the ground? (b) what is the maximum distance that the trebuchet can be from the castle wall to be in range? (c) how high will the stones go? show all your work.