Energy

• Work is done when a force moves an object through a distance.

• The ability to do work or cause change is called energy

• Energy is measured in joules.

• Two basic kinds of energy are kinetic and potential energy.

• The energy of motion is called kinetic energy

• Energy that is stored and held in readiness is called potential energy

• When you raise a book or compress a spring, you give the object potential energy.

• Mechanical energy is the energy associated with the motion or position of an object.

• Mechanical energy can be kinetic or potential energy.

Types of Energy

• thermal energy• electrical energy• chemical energy• electromagnetic energy• nuclear energy

Thermal (Heat) Energy

• Thermal energy is the total potential and kinetic energy of particles in an object.

• When the thermal energy of an object increases, the object becomes warmer.

Electrical Energy

• Moving electrical charges produce electricity, and the energy they carry is called electrical energy

• Example: lightening

Chemical Energy

• Chemical energy is potential energy stored in chemical bonds that hold chemical compounds together.

• Example: when you digest food, you are breaking the chemical bonds of glucose to gain chemical energy

Nuclear Energy

• Nuclear energy is potential energy stored in the nucleus of an atom.

• Power plants use this energy to make electricity

Electromagnetic Energy

• Electromagnetic energy, such as light, travels in waves that have some electrical properties and some magnetic properties.

• examples: x-rays, microwaves

Energy Transformation

• A change from one form of energy to another is called an energy transformation

• For example, a toaster converts electrical energy to thermal energy.

• Your body converts the chemical energy in the food you eat to the mechanical energy you need to move your muscles and to the thermal energy your body uses to maintain its temperature.

The Law of Conservation of Energy

• Energy cannot be created nor destroyed• This means that the total amount of energy is

the same before and after any process.

Fossil Fuels

• Fossil fuels can be burned to release the potential chemical energy stored millions of years ago.

• The process of burning fuels is called combustion.

• Combustion changes the fuel’s chemical potential energy to thermal energy.

Difference between natural gas and gasoline

• Natural gas is a fossil fuel, it comes right from the ground.

• Gasoline is a refined product made from petroleum (a.k.a. crude oil)