P2.2 Energy adds up Flashcards
State the law of conservation of energy.
The law of conservation of energy is that energy can not be created or destroyed; only transferred.
State the types of energy stores and describe them.
Chemical energy store - Energy to do with food, fuel and batteries.
Thermal energy store - Energy to do with hot objects / as a result of motion in their particles.
Kinetic energy store - Energy to do with moving objects.
Gravitational potential energy store - Energy to do with position in a gravitational field ( objects above the ground) .
Elastic energy store - Energy to do with changing shape, squashing or stretching.
Define chemical (store of) energy.
Chemical store of energy is energy stored in foods , fuels and batteries.
Define thermal (store of) energy.
Thermal store of energy is energy to do with hot objects / as a result of motion in their particles.
Define kinetic (store of) energy.
Kinetic store of energy is energy to do with moving objects .
Define gravitational potential (store of) energy.
Gravitational potential store of energy is energy to do with position of the object in a gravitational field ( objects above the ground) .
Define elastic (store of) energy.
Elastic store of energy is energy to do with squashing, stretching or changing shape of an object.
State three ways that energy is transferred between stores.
Electric current, light , sound and heat are ways of transferring energy between stores.
Define ‘dissipated’.
Dissipated : Energy that has become spread out or ‘wasted’ by heating the environment.
Suggest how you can save fuel.
If you transfer more energy to the useful store, you can save fuel.
For example, In a car you want the burning fuel to transfer energy to the store that you want (the kinetic store of the car), not to other stores that you don’t want (such as a thermal store). You want the car to move, not to heat up.
Can energy explain why things happen? Why?
Energy can not explain why things happen. Energy can tell what changes are possible, but it is forces that can explain why things happen. For example, you can put fuel in a car but that does not make the car move. The force provided by the engine makes the car move.
State an object that stores gravitational potential energy.
Any object above the ground stores gravitational potential energy (e.g a computer on a desk).
State an object that stores kinetic energy.
Any moving object stores kinetic energy (e.g a moving car).
State an object that stores thermal energy.
Any hot object stores thermal energy (e.g a hot chocolate).
State an object that stores elastic potential energy.
Any object that is squashed/stretched/changed shape stores elastic potential energy (e.g a stretched rubber band).
