Gravitational Potential Energy When something is lifted, work is done on the object against the pull of gravity. This work is converted to a form of potential energy called gravitational potential energy.

The law of conservation of energy states that energy can neither be created nor destroyed - only converted from one form of energy to another. This means that a system always has the same amount of energy, unless it's added from the outside.

In its most common definition, energy is the ability to do work. In other words, everything that can do work has energy. In the case of energy, doing work is also known as causing or making change. Energy is either transformed or transferred every time work is being done.

Energy is what makes things go, run, or happen. Energy can be changed from one form to another. When energy changes form, some of it is turned into heat.

Natural gas meets 20% of world energy needs and 25% of United States needs. Natural gas is mainly composed of methane (CH4) and is a very potent greenhouse gas. There are two types of natural gas.

Energy cannot be created or destroyed, but it can be transferred and transformed. There are a number of different ways energy can be changed, such as when potential energy becomes kinetic energy or when one object moves another object.

Renewable Energy in the United States Renewable energy generates about 20% of all U.S. electricity , and that percentage continues to grow.