A motorist traveling 25 m/s blows a red light. 5 seconds later a police officer parked at the corner, begins pursuit on his motorcycle at 35 m/s. How long does the chase last

Astone weighing 1.5 kilograms is resting on a rock at a height of 20 meters above the ground. the stone rolls down 10 meters and comes to rest on a patch of moss. the gravitational potential energy of the stone on the moss is joules.