1.
State what is meant by a kinetic energy store.
[1 mark]
- energy of a moving object
JD SCIENCE
P5 Energy
Indicative marking points. Award marks for equivalent scientific or mathematical wording. Do not issue this sheet with the student worksheet.
2.
State what is meant by a gravitational potential store.
[1 mark]
- energy due to height in a field
3.
State what is meant by an elastic store.
[1 mark]
- energy in a stretched spring
4.
State what is meant by conservation of energy.
[1 mark]
- energy is not created or destroyed
5.
State what is meant by efficiency.
[1 mark]
- useful energy / total energy
6.
State what is meant by thermal conductivity.
[1 mark]
- how well a material conducts heat
7.
State what is meant by specific heat capacity.
[1 mark]
- energy to raise 1 kg by 1°C
8.
State what is meant by power.
[1 mark]
- energy transferred per second
9.
State what is meant by work done.
[1 mark]
- energy transferred by a force
10.
State what is meant by a non-renewable energy resource.
[1 mark]
- cannot be replaced in a lifetime
11.
Grace is asked about a kinetic energy store in a OCR Physics paper.
(a) [2 marks]
- ½mv²
(b) [3 marks]
- faster or heavier means more KE
12.
Grace is asked about a gravitational potential store in a OCR Physics paper.
(a) [2 marks]
- mgh
(b) [3 marks]
- increases when lifted
13.
Grace is asked about an elastic store in a OCR Physics paper.
(a) [2 marks]
- ½ke²
(b) [3 marks]
- provided the limit of proportionality is not exceeded
14.
Grace is asked about conservation of energy in a OCR Physics paper.
(a) [2 marks]
- transferred between stores
(b) [3 marks]
- total is constant in a closed system
15.
Grace is asked about efficiency in a OCR Physics paper.
(a) [2 marks]
- can be a percentage
(b) [3 marks]
- never more than 100%
16.
Grace is asked about thermal conductivity in a OCR Physics paper.
(a) [2 marks]
- low for insulators
(b) [3 marks]
- cavity walls reduce transfer
17.
KE of 3 kg at 4 m/s
[3 marks]
- Final answer: 24 J
18.
GPE of 3 kg raised 7 m (g=10)
[3 marks]
- Final answer: 210 J
19.
Efficiency if 80 J useful from 200 J
[3 marks]
- Final answer: 40%
20.
Power if 600 J is transferred in 12 s
[3 marks]
- Final answer: 50 W
21.
SHC: 8000 J heats 1 kg by 4°C. c =
[3 marks]
- Final answer: 2000 J/kg°C
22.
Work done by a 20 N force over 3 m
[3 marks]
- Final answer: 60 J
23.
Grace carries out a OCR-style required practical linked to energy stores and transfers. This is a typical OCR required-practical style question.
(a) [2 marks]
- Independent: the independent variable for this topic
- Dependent: the measured outcome
(b) [2 marks]
- keep all other variables constant
- so the test is fair / only one variable is changed
(c) [2 marks]
- repeat and calculate a mean / use a tighter method
24.
Grace carries out collecting valid data for energy stores and transfers. This is a typical OCR required-practical style question.
(a) [2 marks]
- Independent: a chosen factor
- Dependent: a quantitative measurement
(b) [2 marks]
- calibrated instrument
- so the test is fair / only one variable is changed
(c) [2 marks]
- systematic error from zero error
25.
Grace carries out drawing a graph for energy stores and transfers. This is a typical OCR required-practical style question.
(a) [2 marks]
- Independent: x-variable
- Dependent: y-variable
(b) [2 marks]
- same scale / same apparatus
- so the test is fair / only one variable is changed
(c) [2 marks]
- not drawing a line of best fit through the trend
26.
Grace carries out evaluating a method about energy stores and transfers. This is a typical OCR required-practical style question.
(a) [2 marks]
- Independent: method change
- Dependent: precision / accuracy
(b) [2 marks]
- same sample size
- so the test is fair / only one variable is changed
(c) [2 marks]
- too few repeats
27.
Compare a kinetic energy store with a gravitational potential store.
[4 marks]
- energy of a moving object
- energy due to height in a field
- give one linked difference
28.
Compare a gravitational potential store with an elastic store.
[4 marks]
- energy due to height in a field
- energy in a stretched spring
- give one linked difference
29.
Compare an elastic store with conservation of energy.
[4 marks]
- energy in a stretched spring
- energy is not created or destroyed
- give one linked difference
30.
Compare conservation of energy with efficiency.
[4 marks]
- energy is not created or destroyed
- useful energy / total energy
- give one linked difference
31.
Apply your knowledge of specific heat capacity to this situation: E = mcΔθ
[3 marks]
- E = mcΔθ
32.
Apply your knowledge of power to this situation: P = E/t
[3 marks]
- P = E/t