# Physics

• Created by: Amy-C
• Created on: 11-05-18 10:00
Energy sources
Thermal / Kinetic / Gravitational Potential / Elastic Potential / Chemical / Magnetic / Electrostatic / Nuclear
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What is a system?
A system is just a fancy word for a single object (e.g.the air in a piston) or a group of objects (e.g.two colliding vehicles)
2 of 24
Describe the energy transfers that occur when a car collides with a stationary object
The normal contact force between the car and the object does work. It causes energy to be transferred from the car's kinetic energy store to other energy stores, e.g. the elastic potential and thermal energy stores of the object and the car body.
3 of 24
If energy is transferred to an objects kinetic energy store, what happens to its speed?
Anything that is moving has energy in its kinetic energy store. Energy is transferred to this store when an object speeds up and is transferred away from this store when an object slows down
4 of 24
Give the equation for finding the energy in an objects gravitational potential energy store
Gravitational Potential Energy = Mass x Gravitational Field Strength x Height
5 of 24
What kind of energy store is energy transferred to when you compress a spring?
Stretching and squashing an object can transfer energy to its elastic potential energy store
6 of 24
What does the variable 'e' stand for in the equation for energy in an elastic potential energy store?
Extension
7 of 24
What is the definition of the specific heat capacity of a material? (RP)
Specific heat capacity is the amount of energy needed to raise the temperature of 1 kg of a substance to 1 Degrees Celsius
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Suggest why a material with a high specific heat capacity is better suited for use in a heating system than a material with a low specific heat capacity
It keeps in more heat
9 of 24
True of False? Energy can be destroyed
FALSE
10 of 24
Give two equations to calculate power
Power = Energy Transfer/Time OR Power = Work Done/Time
11 of 24
True or False? A high thermal conductivity means there is a high rate of energy transfer
TRUE
12 of 24
How can you reduce unwanted energy transfers in a machine with moving components?
Lubrication and thermal insulation
13 of 24
Give 4 ways to prevent unwanted energy transfers in a home
Cavity wall insulation / Loft insulation / Double glazed windows / Draught excluders
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True or False? Thicker walls make a house cool down quicker
FALSE
15 of 24
Give the equation that relates efficiency to power
Efficiency = Useful Power Output /Total Power Input
16 of 24
Name the renewable energy resources
The sun (Solar) / Wind / Water Waves / Hydro-electricity / Bio-fuel / Tides / Geothermal
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What is the difference between renewable and non-renewable energy resources?
Renewable: Never run out / Non-renewable: Will all run out one day
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Give an example of how a renewable energy resource is used in everyday life
Solar water heaters work by using the sun to heat water which is then pumped into radiators in the building
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Explain why solar power is considered to be a fairly reliable energy resource
Because it is only really reliable in the daytime
20 of 24
Give one environmental impact of using wave power to generate electricity
The main problems are disturbing the seabed and the habitats of marine animals, spoiling the view and being a hazard to boats
21 of 24
Describe how you can reduce the acid rain caused by burning coal and oil
Acid rain can be reduced by taking the sulfur out before the fuel is burned, or cleaning up the emissions
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Give one environmental benefit of using nuclear power
Nuclear power is clean but the waste is very dangerous and difficult to dispose of
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Explain why the UK plans to use more renewable energy resources in the future
Because non-renewable resources damage the environment and they will eventually run out
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## Other cards in this set

### Card 2

#### Front

What is a system?

#### Back

A system is just a fancy word for a single object (e.g.the air in a piston) or a group of objects (e.g.two colliding vehicles)

### Card 3

#### Front

Describe the energy transfers that occur when a car collides with a stationary object

### Card 4

#### Front

If energy is transferred to an objects kinetic energy store, what happens to its speed?

### Card 5

#### Front

Give the equation for finding the energy in an objects gravitational potential energy store