Illustration of a ball rolling down a ramp, changing colour to show the relationship between gravitational potential energy and kinetic energy. This is also shown on the graph at top left, and by the colours of the ramp. At the start, the ball is high up on the ramp (blue) and it has high potential energy due to gravity pulling it down towards the floor. As the ball rolls down the ramp, its potential energy is converted into kinetic energy as its speed increases (purple). As it hits the floor, the ball is travelling at its maximum speed and its kinetic energy is at a maximum (red).