Oxford Revise AQA GCSE Combined Science Foundation | Chapter P1 answers

P1: Energy stores and transfers

Question Answers Extra information Mark AO / Specification reference
01.1 gravitational potential   1

AO1

6.1.1.1

01.2 joule, J   1

AO1

6.1.1.2

01.3 kinetic   1

AO1

6.1.1.1

02.1 energy in a chemical store is transferred to a kinetic store   1

AO1

6.1.1.1

02.2 \(
\text { power }=\frac{\text { energy transferred }}{\text { time }}
\)
  1

AO1

6.1.1.4

02.3 \(\begin{align}& \frac{312\ 000}{60} \\& =52\ 000\end{align}\)  

1

1

AO2
02.4 W   1

AO1

6.1.1.4

03.1 kinetic energy = 0.5 × mass × (speed)2   1

AO1

6.1.1.2

03.2 kg is a standard unit   1

AO2

6.1.1.2

03.3

30 cm

there is the greatest energy in the gravitational potential energy store

 

1

1

AO3

6.1.1.2

04.1 (their) mass/weight   1 AO1
04.2

doubled

doubled

is

 

1

1

1

AO2

6.1.1.2

04.3 chemical also accept kinetic 1

AO2

6.1.1.1

05.1

created

destroyed

accept in either order 1

AO1

6.1.2.1

05.2 there is no net change to the total energy   1

AO1

6.1.2.1

05.3

is not

energy is transferred out of the system

because it no longer has kinetic/potential energy/mechanical energy

accept energy is wasted/dissipated

accept change to either kinetic or potential energy

1

1

1

AO1

AO2

6.1.2.1

06.1

gravitational potential

kinetic

thermal

 

1

1

1

AO1

6.1.1.1

06.2 elastic store   1

AO2

6.1.1.2

06.3 less energy to be returned to the gravitational store   1

AO2

6.1.2.1

07.1 gravitational potential energy = mass × gravitational field strength × height   1

AO1

6.1.1.2

07.2

40 × 10 × 9.8

= 3920 (J)

 

1

1

AO2

6.1.1.2

07.3

0.5 × 40 × 122

= 2880 (J)

 

1

1

AO2
07.4 3920 – 2880 = 1040   1 AO2
08.1 gravitational potential energy = mass × gravitational field strength × height   1

AO1

6.1.1.2

08.2 mass = 0.05 kg accept 5 × 10-2 kg 1

AO2

6.1.1.2

08.3

energy = 0.05 × 10 × 1.5

= 0.75 (J)

 

1

1

AO1

AO2

6.1.1.2

08.4 some energy is wasted/not transferred to a store that is useful/not all the energy transfer is useful/some energy is transferred to the thermal store of the air   1

AO3

6.1.1.1

6.1.2.1

6.1.2.2

09.1
  • use a ruler to measure the initial height/height after 10 swings
  • use a digital balance to measure the mass of the bob
  • use the equation for gravitational potential energy to work out the energy before and after 10 swings
  • find the difference between the initial and final energy/subtract the final from the initial energy
 

1

1

1

1

AO1

6.1.1.2

09.2

measuring the height

sensible suggestion e.g., fix a ruler, use a video camera

 

1

1

AO3

6.1.1.2

10.1 energy that is no longer useful/stored in less useful ways   1

AO1

6.1.2.1

10.2 \(
\text { efficiency }=\frac{\text { useful output energy transfer }}{\text { total input energy transfer }}
\)
  1

AO1

6.1.2.2

10.3 \(
\text { efficiency }=\frac{12}{20}=0.6
\)

accept 0.6 with no working for two marks

60% scores one mark

1

1

AO2

6.1.1.2

10.4

car B

has a lower efficiency so wastes more energy

 

1

1

AO3

6.1.1.2

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