physics topic one

Question 1

describe mechanical force pathways

Answer 1

Mechanically – when a force acts and an object moves

Question 2

describe electrical force pathways

Answer 2

Electrically – when an electric current flows

Question 3

describe heating force pathways

Answer 3

Heating – a temperature difference between objects

Question 4

describe radiation force pathways

Answer 4

Radiation – electromagnetic waves or sound

Question 5

what happens to all wasted energy

Answer 5

dissipates to the surroundings

Question 6

what is work done

Answer 6

work done is the amount of energy transferred by a force

Question 7

what is the formula for work done

Answer 7

Work (J) = Force (N) x Distance (m)

Question 8

what is electrical work

Answer 8

Electrical work is work
done when charge flows in a circuit is the amount of energy
transferred.

Question 9

what is the formula for energy transferred / electrical work

Answer 9

Energy transferred (Work) (J) = Charge flow (Q) x Potential difference (V)

Question 10

what do energy do stretched or bent objects have

Answer 10

Stretched or bent objects have elastic energy (Ee) if they have the ability to recover to their original shape and dimensions.

Question 11

what is spring constant measured in

Answer 11

N/m

Question 12

what energy does an object gain when it raises above ground

Answer 12

When an object is raised above ground level it gains
gravitational potential energy

Question 13

what is gravitational field strength measured in

Answer 13

N/kg

Question 14

what is specific heat capacity

Answer 14

the amount of energy required to raise the temperature of 1 kg of a substance by one degree Celsius.

Question 15

what is the specific heat capacity required practical

Answer 15

1) Measure energy (transferred) using joulemeter or ammeter, voltmeter and stopclock
2) Measure mass of metal block using electric balance
3) Measure temperature change using thermometer
4) Use E = mcθ to calculate specific heat capacity

Valid results:
* Repeat practical and calculate a mean
* Plot a graph of temperature against time and use linear section of graph for temperature
change

Question 16

what is the thermal insulators required practical

Answer 16

1) Use a measuring cylinder to measure volume of water
2) Put hot water in the metal can
3) Measure initial and final temperature with a thermometer
4) Use a stopwatch to measure 5 minutes
5) Calculate temperature decrease
6) Repeat with different number of layers of newspaper
7) Repeat with no layers of newspaper - as a control

Question 17

what is power

Answer 17

the rate at which energy is transferred which is the rate work is done

Question 18

what is power measured in

Answer 18

watts

Question 19

what is thermal insulation used for

Answer 19

Thermal insulation is often used to reduce unwanted energy transfers.

Question 20

what is thermal conductivity

Answer 20

how quick heat is transferred though a material so The higher the thermal conductivity, the quicker heat is transferred through the material.

Question 21

what are non-renewable energy sources

Answer 21

energy sources will eventually run out

Question 22

what are renewable energy sources

Answer 22

Renewable energy sources are those which can replenish
themselves in the short term, and so will never run out.

Question 23

how does a coal fired power station work

Answer 23

coal has chemical energy
when burnt, heat energy
used to boil water/make steam
used to turn turbine(s)
which now have kinetic energy
turbines turn generators
where kinetic energy is transferred to electrical energy

Question 24

advantages of renewable energy

Answer 24

Can be used over again

Doesn’t release Carbon
Dioxide

Question 25

disadvantages of renewable energy

Answer 25

Unreliable – not always
sunny or windy

Usually expensive to build

Question 26

advantages of non renewable energy

Answer 26

Reliable

Question 27

disadvantages of non renewable energy

Answer 27

Releases Carbon Dioxide –
greenhouse gas leading to global warming

Can only be used once