Q1. Draw an energy bar chart for each of the following situation. If it matters, write down where the zero of potential gravitational energy is taken to be (without specifying numbers).
- A car runs out of gas and coast up a hill until finally stopping. Take the system to be car + Earth.
- A ball starts from rest on the top of one hill, rolls without friction through a valley and just barely makes it to the top of an adjacent hill. Take the system to be ball + Earth.
- A brick is held above a spring that is standing on the ground. The brick is released from rest and falls on the spring. A short time later the spring reaches its maximum compression. Take the system to be brick + spring + Earth.