Energy

Question 1

What is a system?

Answer 1

an object or group of objects

Question 2

Describe the energy changes when a ball is thrown upwards

Answer 2

Kinetic energy into GPE and thermal

Question 3

Describe the energy changes when an object hits an obstacle

Answer 3

Kinetic into Thermal and sound

Question 4

Describe the energy changes in a torch

Answer 4

Chemical into electrical into thermal and light

Question 5

State the equation and all units for kinetic energy

Answer 5

kinetic energy (J) = 0.5 × mass (kg) × speed Squared (m/s)

Question 6

State the equation and all units for GPE

Answer 6

g.p.e. (J) = mass (kg) × gravitational field strength(N/kg) × height (m)

Question 7

Define specific heat capacity

Answer 7

the amount of energy required to raise the temperature of one kilogram of the substance by one degree Celsius.

Question 8

State the units for specific heat capacity

Answer 8

J/kg °C

Question 9

Define Power

Answer 9

Rate at which energy is transferred into a new form

Question 10

State the equation with all units for Power.

Answer 10

Power (W) = energy (J)/ time (s)

Question 11

Define 1 W

Answer 11

An energy transfer of 1 joule per second

Question 12

State the conservation of energy

Answer 12

Energy can be transferred usefully, stored or dissipated, but cannot be created or destroyed.

Question 13

Define thermal conductivity

Answer 13

How well a material can insulate. The higher the thermal conductivity of a material the higher the rate of energy transfer by conduction across the material.

Question 14

How can heat loss from a building be minimised?

Answer 14

Using thicker walls and materials with a lower thermal conductivity

Question 15

Define efficiency

Answer 15

How effective a device is at converting its input energy into a useful output form of energy

Question 16

State the equation for efficiency

Answer 16

efficiency = useful output energy / total input energy

Question 17

State the 3 fossil fuels

Answer 17

Coal, oil and gas

Question 18

Define a renewable energy resource

Answer 18

One that can be replenished and won’t run out

Question 19

State the advantages of fossil fuels

Answer 19

Reliable
Short start up time of a few hours
cheap
can be used in many locations
doesn't produce radioactive waste

Question 20

State the disadvantages of fossil fuels

Answer 20

Non renewable
Will run out
Produces carbon dioxide which leads to global warming
Causes acid rain

Question 21

State the advantages of nuclear power

Answer 21

Reliable
A very concentrated source of energy
No carbon dioxide release
Doesn’t cause acid rain

Question 22

State the disadvantages of nuclear power

Answer 22

Slow start up time of a few days
Causes Radioactive waste
High decommissioning costs
Non renewable

Question 23

State the advantages of solar power.

Answer 23

Renewable
Wont run out
no fuel cost
no cardon dioxide
Doesn't cause acid rain

Question 24

State the disadvantages of solar power

Answer 24

Unreliable
Expensive to buy
Don’t get much energy so need lots of solar cells

Question 25

State the advantages of wind

Answer 25

``` Renewable Wont run out no fuel cost no cardon dioxide Doesn't cause acid rain ```

Question 26

State the disadvantages of wind

Answer 26

Unreliable Visual pollution Noise pollution Don't get much energy so need a large area of wind turbines

Question 27

State the advantages of hydroelectric

Answer 27

``` Short start up time Renewable Wont run out no fuel cost no cardon dioxide Doesn't cause acid rain ```

Question 28

Disadvantages of hydroelectric

Answer 28

Expensive to buy the dam Flooding of surrounding areas Damage to animal habitats

Question 29

Advantages of geothermal

Answer 29

``` Short start up time Renewable Wont run out Low fuel cost no cardon dioxide Doesn't cause acid rain ```

Question 30

Disadvantages of geothermal

Answer 30

Expensive to drill | Only suitable in certain locations

Question 31

Advantages of wave power

Answer 31

``` Renewable Wont run out Low fuel cost no cardon dioxide Doesn't cause acid rain ```

Question 32

Disadvantages of wave power

Answer 32

Unreliable Difficult to maintain and repair Restricts shipping lanes

Question 33

Advantages of tidal

Answer 33

``` Reliable - as tides can be predicted Renewable Wont run out Low fuel cost no cardon dioxide Doesn't cause acid rain ```

Question 34

Disadvantages of tidal

Answer 34

Difficult to maintain and repair | Restricts shipping lanes

Question 35

Advantages of Biomass

Answer 35

Reliable Renewable Carbon neutral

Question 36

Disadvantages of Biomass

Answer 36

Release carbon dioxide | Take up land which can be used for crops