Two marbles of masses m and 2m are dropped from a height h. Compare their kinetic energies when they reach the ground.

a 1 kg flower pot has 20 J of energy when resting on a window ledge. how high is the window from the groud? take the ground to be the reference level 0.

At the local playground, a child on a swing has a speed of 2.22 m/s when the swing is at its lowest point.To what maximum vertical height does the child rise, assuming he sits still and "coasts"? Ignoring air resistance.

Using energy techniques solve the following problem(s)A firework cannon fires its 0.8 kg payload straight up from a starting height of 1.2 m (which is the length of the cannon) with an initial velocity of 80 m/s.  (a) What is the initial gravitational potential energy of the payload relative to the ground? (b) What is the initial kinetic energy of the payload? (c) When it gets to its highest point, the payload's kinetic energy will have all been converted to gravitational potential energy.  Use this knowledge and your answers from (a) and (b) to calculate the maximum height of the payload using energy techniques (instead of kinematics).  Notice that we are still using the fact that the vertical velocity at its highest point is zero

A rocket is attached to the back of a train engine which pushes the engine along a curvy track with an applied force of 1,000 Newtons. The engine has a mass of 500 kg. The total length of track is 800 meters. Starting from rest, what will be the train's speed at the end of the track? (You must use energy methods for credit on this problem not kinematics.)

A block with mass m = 0.10 kg is released from rest at point y = 1.0 m and slides down along a frictionless track, its speed in (m/s) at the end of the track is: