Choose the correct description to go with this work-energy diagram.

• A car going too fast locks the brakes and skids to a stop, on a level road. System is the car only. Neglect air resistance. Click here to choose this answer.
• A football player kicks a ball for an extra point. System is the ball and the Earth, from just before the kick to the moment the ball passes through the goal posts. Neglect air resistance. Click here to choose this answer..
• You are riding your bicycle down a very steep hill at a constant speed with your hand on the brake all the time. System is you, the bicycle, and the Earth. Click here to choose this answer.
• A golf ball is rolling up a gentle slope, slowing down as it goes. System is ball + earth. Neglect rolling friction. Click here to choose this answer.
• A skydiver falls the last 100 m before opening his parachute at a constant speed. System is skydiver and atmosphere, but not the earth below. Click here to choose this answer.