Chapter 2 Energy and Energy Transformations
Energy is the ability to cause a change. Can you think of ways energy might cause a change?
Kinetic energy is the energy of motion. Kinetic energy depends on the speed and the mass of the object. The faster the object moves, the more kinetic energy it has. Kinetic energy also depends on the mass of the object. If two objects move at the same speed, the object with more mass also has more kinetic energy.
*Example: the blue car is traveling 25 m/s and has a mass of 1500 kg. The green car is traveling at 15 m/s and has a mass of 1500.
*Which car has more kinetic energy?
Now a truck with the speed of 15 m/s and a mass of 800 kg is on the road.
*Between the truck and the green car which has more kinetic energy?
Potential energy is stored energy due to the interactions between objects or particles. There are three main types of potential energy.
Gravitational potential energy is stored energy between an object and Earth.
Elastic potential energy is in a rubber band. It is stored in objects that are compressed or stretched. When you release the end of the rubber band then the elastic potential energy is converted to kinetic energy.
Chemical potential energy is energy stored in chemical bonds between atoms. The body uses chemical potential in foods for all activities. Also chemical potential energy is used in gasoline to power cars and busses.