Physics Unit 1

Front 1

Give 2 ways the nature of a surface could be changed so that the surface emits more infrared radiation

Back 1

make a surface darker and more matt.

Front 2

Describe the particles in a gas in terms of their arrangement, kinetic energy and movement

Back 2

Gases are free to move, not arranged in a patern. They move in random directions and at high speeds with high kinetic energies.

Front 3

Describe the process of heat transfer by conduction

Back 3

particles vibrate faster than others. They pass extra kinetic energy to their neighbours..

Front 4

Explain why heat rises

Back 4

Heated air expands because it becomes less dense than the surrounding cooler and rises.

Front 5

a and b

Back 5

a) When air is 15°C and water 60°C the water will cool quicker because the temperature difference is greater so the rate of heat transfer will be greater.
b) When you replace the plastic cup for a metal cup the rate of heat transfer will be increased because metal is better conductor.

Front 6

Back 6

2ai) radiation
aii) conduction
aiii) convection
b) black is good absorbers of infrared radiation

Front 7

Define 'Condensation'

Back 7

When a gas changes state into a liquid.

Front 8

Explain how a coat keeps you warm.

Back 8

Coats help trap a layer of air around the body
which will act as an insulator and helps stop heat loss by conduction.

Front 9

Expalin how thr mirrored surfaces on the inside of a vacuum flask help reduce heat transfer.

Back 9

They reflect infrared radiation and so help reduce heat transfer by radiation.

Front 10

Give 3 ways of increasing the rate of condensation of a gas onto a cool surface.

Back 10

lowering the temperature of the gas
increasing concentration of the gas
increasing density of the gas.

Front 11

Explain how having large ears could be advantage to an animal living in a hot climate.

Back 11

The animal will have a larger surface area this means this will increase the rate of heat transfer away from the animals body keeping the animal cool.

Front 12

Explain, in terms of particle energies, how sweating will help keep an animal cool.

Back 12

The particles of sweat that evaporate have high energies. When they evaporate, the average energy of the remaining particles decreases and so the temperature of the sweat decreases, helping to cool the animal.

Front 13

a b and c

Back 13

a) The larger the surface area of an object , the higher the rate of heat transfer will be. The heat sink has fins which give it a large surface area so it will have a high rate of heat transfer.
The heat sink is in direct contact with the whole of the processor which will maximise the heat transfer by conduction between the processor and the heat sink.
b)The heat sink is made up from metal which is a good conductor and so will be able to conduct heat quickly away from the processor and the heat sink.
c) A fan will increase the difference in temperature between the heat sink and its surroundings and so will increase the rate of heat transfer.

Front 14

Give 3 methods of insulating a house

Back 14

loft insulation caity wall insulation and double glazing

Front 15

Define ''Payback time''

Back 15

The amount of time it takes for the initial cost to equal the money saved

Front 16

what type of heat transfer does draught-proofing help to reduce?

Back 16

convection

Front 17

Define specific heat capacity

Back 17

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

Front 18

Name 3 different renewable sources

Back 18

wind waves solar

Front 19

Describe the direction of vibrations in a longitudinal wave.

Back 19

In transverse waves the vibrations are perpendicular to the direction of energy transfer of the wave

Front 20

Explain how pump storage systems work

Back 20

'Spare' night time electricity is used to pump water up to a reservoir. This can then be released quickly when extra electricity is needed.

Front 21

give 2 ways in which coal as an energy source causes problems

Back 21

It releases greenhouse gases.
It causes acid rain

Front 22

Describe the major problems with nuclear power to provide energy

Back 22

nuclear fission results in the production of waste, which is very difficult and expensive to dispose of safely.

Front 23

Explain what it is meant by biofuels

Back 23

Organic matter that can be burnt to release energy.

Front 24

Describe what is meant by geothermal energy

Back 24

Heat energy from inside the earth

Front 25

Define renewable energy

Back 25

The source of the energy will never run out

Front 26

Give 2 disadvantages of using geothermal energy to generate electricity

Back 26

There are few suitable locations for geothermal power plants, since they can only be built in volcanic areas with hot rocks close to the surface

The cost to set up a geothermal power plant is high relative to the energy available

Front 27

Give two reasons why some people might oppose the wind farm development

Back 27

Causes visual and noise pollution
Disturb local wildlife.

Front 28

Explain why the National Grid uses step-up transformers

Back 28

Step-up transformers step up the voltage of the electricity supply , allowing the electricty to be transmitted at high voltages (and low currents) to reduce the amount of energy lost as heat.

Front 29

Apart from wind, solar and hydroelectric
Suggest 2 other renewable energy sources they could use.

Back 29

wave, tidal, geothermal.

Front 30

Apart from reliability
Suggest two other factors you should consider when deciding which method of electricity generation to use.

Back 30

Any 2 from
set-up time
set-up cost
running cost
impacts on environment
social impact

Front 31

what type of wave are EM waves- transverse or longitudinal?

Back 31

Transverse

Front 32

Give the formula for calculating the speed of wave.

Back 32

wave speed = frequency x wavelength

Front 33

Describe what happens when a wave passes through a narrow gap.

Back 33

Diffraction occurs- the wave spreads out.

Front 34

True or False: a wave entering a new medium along the path of the normal will be refracted.

Back 34

True

Front 35

Describe the direction of vibrations in a longitudinal wave.

Back 35

In a longitudinal wave, the vibrations are parallel to the direction of travel/energy transfer