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Key Idea 1
The Many Faces of Energy
Concept Question: How do scientists describe the various forms of energy?

 An electric heater

Suppose it is a cold, winter day. You are getting chilly, so you decide to turn on your household’s electric heater. How exactly does the heater warm up your house?

In order to heat up a house, we need energy. Where did the heater obtain energy from, so that this energy could be released to the surrounding air?

Remember that the heater is an electric heater; it is plugged into an electrical socket. Therefore, inside of the heater, electricity is passed through a special wire that has high resistance, so that much of the electrical energy is converted to thermal energy-increased motion of the atoms in the wire. But then, where does the electricity come from?

Electricity is transported to your house through electrical transmission lines, which run back to a power plant. Most power plants in North America produce electricity using generators. Inside of a generator, a coil of wire spins within a magnetic field. This creates a stream of electrons, which travel through the power lines. But how does the coil of wire begin to spin?

Electrical transmission lines  A coal-burning power plant