Attention Getting Question:
Does a car that is motionless have energy? The answer is yes! Because they have the potential to move, they have potential energy. Let’s find out why.
Energy is the ability to cause motion or create change in matter. Everything that moves has energy. Cars and people need energy in order to move. Cars get their energy from gasoline and you get your energy from the foods you eat.
Kinetic energy is the energy of motion. Anything that is moving has this type of energy. Think about your classroom right now. There is kinetic energy all around you. Someone may be moving their pencil to write notes about kinetic energy as they are watching this video. Another person may be moving their fingers on an iPad to research more about energy. Think about the classroom clock. The hands on the clock are always moving. Even things that you cannot see move have kinetic energy. Blood is flowing through your body and the gases in the air are in constant motion. What are some other examples of kinetic energy outside the classroom?
Potential energy is energy that is stored. Something that has a greater mass, is higher above the ground, and moves faster has more potential energy. A roller coaster stopped at the top of a hill has more potential energy than a bike stopped on top of a hill. Both have stored energy, but the roller coaster has more because it has more mass, is higher above the ground, and moves faster than a bicycle. Your body has potential energy, too. That energy can be used to do work. Look around your classroom again. Can you find examples of potential energy? There is potential energy all around you. A book on a desk could potentially be pushed off. The book on the desk is an example of potential energy. The book falling to the floor is an example of kinetic energy.
Mechanical energy is the total kinetic energy and potential energy. Moving objects have mechanical energy because they possess both kinetic and potential energy.
Let’s think about a skateboarder for a moment. A skateboarder on the top of a hill possesses potential energy. The higher the hill, the more potential energy she has. As she goes down the hill, the potential energy changes into kinetic energy. The kinetic energy increases when she moves faster. If she decides to take a break and rest at the bottom of the hill, she will no longer have kinetic energy, but she will still have mechanical energy. All of the mechanical energy will be her potential energy.
Energy is the ability to cause motion or create change in matter. There are two basic types of energy. Kinetic energy is the energy of motion. Potential energy is the energy that is stored. The combination of kinetic energy and potential energy is called mechanical energy.