# Energy

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• Created by: Zammi10
• Created on: 19-02-15 18:53

Different types of energy are:

SPELCHEK

Energy is conserved as it cannot be created or destroyed so the energy output will equal the energy input. Electrical appliances transfer electrical energy into useful energy however some of it is wasted- it dissipates into the surroundings. It becomes less useful as it spreads out more

In a food proccesor for example, the useful energy is that energy is transferred kinetic energy. Wasted is sound and heat.

Sankey diagrams can be used to show useful energy transfer

Calculating efficiency

Efficiency= Useful energy out / Total energy in (x100)

i.e. 100J of electrical energy is converted into 60J light energy. The efficiency of the bulb is therefore 60/100 x100= 60%

Energy saving lamps are more energy efficient as they transfer more to light energy as less is lost as heat energy (filament heats up in filament lamps)

Kinetic Energy

Kinetic energy formula is: 1/2mv^2

Question: 2Kg mass moves at 3m/s. KE=9J

GPE

The higher up something is, the more GPE it has. As it falls, the GPE is transferred to Kinetic Energy.

Formula is: m…

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