Chapter 1 - Energy

Question 1

What are the different types of energy stores?

Answer 1

Thermal
Kinetic
Gravitational potential
Elastic potential
Chemical
Magnetic
Electrostatic 
Nuclear

Question 2

What is a closed system?

Answer 2

A system where neither matter nor energy can enter or leave.

Question 3

Describe the energy transfer as a person throw a ball into the air?

Answer 3

Chemical energy store of the persons arm to the kinetic energy store of the ball and the arm

Question 4

What is a system?

Answer 4

A system is a fancy word for a single object

Question 5

What happens when a system changes?

Answer 5

Energy is transferred

Question 6

What are closed systems?

Answer 6

Systems where neither matter nor energy can enter or leave. The net change in the total energy of a closed system is always zero

Question 7

What is a kinetic energy store?

Answer 7

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 the store when an object slows down

Question 8

What does the energy in a kinetic energy store depend upon?

Answer 8

The objects mass and speed

The greater the mass and the faster it is going, the more energy there will be in its kinetic energy store.

Question 9

How do you work out kinetic energy?

Answer 9

Kinetic energy = 1/2 x mass (kg) x speed (m/s)^2

Question 10

What does the amount of gravitational potential energy depend upon?

Answer 10

It depends on the objects mass, its height and the strength of the gravitational field the object is in

Question 11

How do you find the change in energy in an objects gravitational potential energy store for a change in height?

Answer 11

Gravitational potential energy= mass (kg) x gravitational field strength (N/Kg) x height (m)

Question 12

What energy change happens with a falling object?

Answer 12

Gravitational potential energy store transferred to kinetic energy store

Question 13

What energy transfer happens when stretching or squashing an object?

Answer 13

Elastic potential energy

Question 14

What is specific heat capacity?

Answer 14

The amount of energy needed to raise the temperature of 1kg of a substance by 1kg

Question 15

What is the conservation of energy principal

Answer 15

Energy can be transferred usefully, stored or dissipated, but can never be created or destroyed

Question 16

What is dissipated energy

Answer 16

Energy that is wasted

Question 17

What is power

Answer 17

Power is the rate of energy transfer, or the rate of doing work. It is measured in watts.

Question 18

What is one watt equal to

Answer 18

One watt = one jewel of energy per second

Question 19

How can you reduce unwanted energy transfers?

Answer 19

Lubrication reduces frictional forces

Heating can occur by conduction and convection therefore installation reduces the rate of energy transfer by heating

Question 20

How does lubrication reduce unwanted energy transfer?

Answer 20

Lubricants can be used to reduce the friction between the object services when they move. This is so they can flow easily between objects and coat them.

Question 21

How does insulation reduce unwanted energy transfers

Answer 21

Insulation traps heat inside

Having thick walls are made from material with a low thermal conductivity traps heat inside homes. The thick of the walls and the lower the thermal conductivity, The slower the rate of energy transfer will be to the building will cool more slowly

Question 22

What are some examples of thermal insulation in homes

Answer 22

Cavity walls: made up of an inner and outer wall with an air gap in the middle. The air gap reduces the amount of energy transferred by conduction through the walls.

Loft insulation : reduces convection currents (a cycle where are particles are constantly being heated, rising, cooling and then sinking)

Double glazed windows: they work in the same way as cavity walls

Draught excluders around doors and windows reduce energy transfers by convection

Question 23

No devise 100% efficient. However what is an exception to this?

Answer 23

Electric heaters. They are usually hundred percent efficient because all the energy in the electrostatic energy store is transferred to use to thermal energy stores

Question 24

What are the three main fossil fuels

Answer 24

Coal
Oil
Natural gas

Question 25

What are the renewable energy sources

Answer 25

``` The Sun Wind Water waves Biofuel Tides Geothermal Hydroelectricityq ```

Question 26

What are the renewable or nonrenewable energy resources for transport

Answer 26

Nonrenewable energy resources: Petrol and diesel powered vehicles used by most cars use fuel created from oil Coal is used in some old-fashioned steam trains to boil water to produce steam Renewable energy resources: Vehicles that run on fuel biofuels or a mix of a buyer for fuel and petrol or diesel

Question 27

What are the renewable and nonrenewable energy resources that can be used for heating

Answer 27

Non renewable energy resources: Coal is Commonly burnt in five places Electric heaters which use electricity generated from nonrenewable energy resources Natural gas is the most widely used fuel for heating homes in the UK. The gas is used to heat water which is then pumped into radiators throughout the home Renewable energy resources A geothermal heat pump uses geothermal energy resources to heat buildings Soda water heaters work by using the sun to heat water Burning biofuel for your using electricity generated from renewable resources

Question 28

What are the pros and cons of wind power

Answer 28

Cons - They spoil the view - You need about 1500 wind turbines to replace one coal fired power station - They can be very noisy - Initial costs are quite high - They on average produce electricity 70 to 85% of the time Pros - there is no pollution except for a little bit when they are manufactured - there are no fuel costs and minimal running costs - no permanent damage to landscape - renewable energy source

Question 29

What are the pros and cons of solar cells a.k.a. solar panels

Answer 29

Pros - there is no pollution - initial costs are high but after that the energy is free and running costs are almost nothing - they are not noisy Cons - You can't increase the power output when there is extra demand - relatively small scale production of energy - only works in daytime

Question 30

What is geothermal power and how does it work

Answer 30

This is possible and volcanic areas where hot rocks lie quite near to the surface. Completely free energy that's reliable and does very little damage to the environment Used to generate electricity or heat buildings directly The main drawbacks with your thermal power are that there aren't very many suitable locations for power plants and that the cost of building a power plant is often high compare to the amount of energy it produces

Question 31

What are the pros and cons of hydroelectric power

Answer 31

Pros - it can provide an immediate response to an increased amount of electricity - there no fuel costs and minimal running costs - useful way to generate electricity on a small scale in remote areas No pollution Cons - big impact on the environment Due to the flooding of the valley. This rocks and vegetation which releases methane CO2 and possible loss of habitat for some species

Question 32

What are biofuels was made from

Answer 32

Biofuels are made from plants and waste

Question 33

What are biofuels

Answer 33

Biofuels are renewable energy sources created from either plant products or animal dung. They can be solid liquid or gas and can be burnt to produce electricity or run cars in the same way as fossil feels

Question 34

How are nonrenewable energy sources cost-effective

Answer 34

While the set up costs of power plants can be quite high compare to other energy resources, the running costs aren't that expensive. Force of yours the nuclear energy or reliable as there is enough also a nuclear fuels to meet current demand

Question 35

How do fossil fuels create environmental problems

Answer 35

Call, oil and gas release CO2 into the atmosphere when they're burnt. The CO2 adds to the greenhouse effect Burning coal and oil also releases sulphur dioxide, which causes acid rain Acid rain can be reduced by taking the sulphur out before the fuel is burned Coal Mining makes a mess of the landscape especially opencast mining Oil spillages cause serious environmental problems affecting mammals and birds that live in and around the area Nuclear-power is clean but the nuclear waste is very dangerous and difficult to dispose of Nuclear fuel is relatively cheap but the overall cost of nuclear-power is high due to the cost of the power plant and final decommissioning

Question 36

Has the use of electricity increase or decreased Since the 20th century

Answer 36

Electricity in the UK has been decreasing slowly as we get better at making appliances more officiant and become more careful with the energy in our own homes Most of our electricity is produced using fossil feels and from nuclear power

Question 37

What is stopping us from using renewable energy

Answer 37

Building new renewable power plants costs money Even if new power plants are built there are still arguments over where to put them Some energy resources that were in power and not as reliable as traditional fossil feels Research on improving the reliability across the renewables take time and money