1. Two cars, one twice as heavy as the other, are lifted to the same height in a service station. How do their potential energies compare? 2. When a car travels at 50 km/h, it has kinetic energy. How...

1. Two cars, one twice as heavy as the other, are lifted to the same height in a service station. How do their potential energies compare?

2. When a car travels at 50 km/h, it has kinetic energy. How much more kinetic energy does it have at 100 km/h?

3. What is the evidence for saying whether or not work is done on an object?