What is Energy? Energy is the ability to cause a change in the motion or position of an object. Work is the transfer of energy that occurs when a force is applied over a distance. W = F x D According to the Law of Conservation of Energy, energy cannot be created or destroyed, but in can be transformed from one type of energy to another or transferred from place to place.

Types of Energy Kinetic Energy is energy in motion. The amount of kinetic energy depends on it mass and speed. More mass or speed means more kinetic energy. A bus going 50 mph has more kinetic energy than a bike going 50 mph. Potential Energy is stored energy. Gravitational potential energy of an object depends on its weight and height. An elephant on top of the school has more gravitational potential energy than a mouse on the first floor. Mechanical Energy equals an object’s total kinetic AND potential energy.

Transforming Energy Friction (like the brakes on a car) transforms mechanical energy into thermal energy. Car slows down, brakes heat up. Your body can change food into movement. Technically, this means transforming the chemical energy in food into mechanical energy (your body moves and grows) An electric power plant can convert the kinetic energy of falling water into electric energy.

Transforming Energy II A microwave oven can change electrical energy into radiant energy (energy carried by electromagnetic waves). A gas stove, on the other hand, transforms the chemical energy of natural gas into thermal energy. (heat)

Energy Resources Fossil Fuels (coal, oil, natural gas) are nonrenewable. We are using them up faster than they can be replaced. All three fossil fuels are still sort of inexpensive, but all contribute to air pollution, climate change, and other environmental harms such as oil spills, strip mining, and such. Nuclear is nonrewable, as uranium will run out, but it does not cause air pollution or release carbon dioxide. However, it creates radioactive waste which is hard to store or get rid of. Used mainly for electricity.

Energy Sources II Coal is burned mainly for electricity. Oil is sometimes used for electricity, made into gasoline for cars and trucks and planes and ships, and turned into plastic and fertilizer. Natural gas is used for heating, cooking, and more and more is used in the USA for electrical generation.

Energy sources, III Renewable energy resources will not run out. Wind is nonpolluting, but only works well in some areas and wind turbines can be noisy, kill birds and bats, and some people don’t like looking at them. Used for electricity. Solar is nonpolluting, but only works well during the day and in sunny areas. Also, large solar farms take up a lot of space. Used for electricity and sometimes heating. Hydroelectric does not create air pollution but is not available everywhere and building dams destroys river habitats. Used for electricity Biomass is readily available, but burning it can cause air pollution. Used for heating, cooking, and fuel for vehicles.