Page 252 - Science Course 3 (Book 1)
P. 252
Mo7-L2b: What is Friction?
Key Concept SUMMARY
What is Friction? What is Friction?
What happens to energy when it is used? Friction transforms mechanical energy into
thermal energy.
Different forms of energy, such as sound and
radiant energy, are used when someone talks
on a cell phone.
When energy changes form, some thermal energy is
always released.
Scientists often refer to thermal energy that cannot be
used as waste energy.
Whenever energy is used, some energy is transformed
into useful energy and some is transformed into waste
energy
Battery
(store of chemical
energy)
Transfered as
electrical energy
Lamp
Transfered as Transfered as
Thermal energy Light energy
Surroundings Surroundings
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