Science Physics P1.2

Forms of energy 2.1
1. Energy exists in different forms such as light, sound,kinetic (movement), nuclear, electric, gravitational potential, elastic potential and chemical
2. Energy can be transferred from one form to another form
3. When a object falls it gains speed, is gravitational potential energy decreases and its kinetic energy increases
Useful energy 2.3
1. Useful energy is energy in the place we want it and the form we want it. wasted energy is energy that is not useful
2. Useful energy and wasted energy both end up being transferred to the surroundings, which become warmer
3. As energy spreads out it gets more and more difficult to use for further energy transfers
Conservation of energy 2.2
1. It is not possible to create or destroy energy.
2. Its only possible to transfer it from one form to another or one place to another
3. Conservation of energy applies to all energy changes
Energy and efficiency 2.4
1. No machine can be 100% efficient. Energy is measured in Joules
2. Measurements to make machines more efficient include reducing : friction,air resistance, electrical resistance, noise due to vibrations
3. Efficiency= useful energy transferred by the appliance x100 total energy supplied to the appliance

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	Created by Rosina Hortop almost 10 years ago