Work Done & Energy Transfer (OCR Gateway GCSE Physics: Combined Science)

Topic Questions

1a5 marks

A tall building needs a lift to move people from one floor to another.

The builder has a choice of three different lifts.

Each lift takes a different amount of time to move between the two floors.

Look at a bar chart of the time taken for each lift.

q19-paper1-june2098-ocr-gcse-physics

a)


i)
Lift C takes 12s to move between the two floors.

Draw a bar for lift C on the bar chart.

[1]
 
ii)
Calculate the mean time of the three lift journeys.


Mean = ...................................................... s [2]

iii)
Explain which lift uses the most power.

 [2]

1b7 marks
b)
i)
One lift uses 50000  for a 12 s journey.
Calculate the power of the lift.
Give your answer to 1 decimal place.

Power = .................................................... W [4]

ii)
When the lift is broken the stairs are used.

Calculate the work done when a 750 N person climbs a distance of 4 m.

Work done = ...................................................... J [3]

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2a2 marks

Four students investigate the work done in moving a trolley.

work done = force × distance

Each student moves a trolley by a different distance using a different force.

Their results are shown in the table.

Student Force (N) Distance moved (m)
A 100 5
B 50 10
C 120 12
D 40 4

a)
Which student does the most work?

Show your working.
[2]
2b1 mark
b)
Which two students do the same amount of work?
[1]
2c2 marks
c)
State two reasons why it is important to repeat measurements in any experiment. 

[2]

2d4 marks
d)
Student C pushes the trolley for 0.5 minutes.

What is the power, in W, used by student C?

Show your working.

Answer: .........................W [4]

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34 marks

A student investigates potential and kinetic energy.

She looks at some data from experiments with motion trolleys and energy.

  • The trolleys are stationary at the top of a ramp and have a gravitational potential energy of 8 J.
  • Each trolley has a mass of 1 kg.

Look at the research data on the trolleys.

Trolley

Velocity at the bottom of the

ramp (m/s)

W 3
X 4
Y 5
Z 6

The student thinks the data is wrong.

Use the data and your understanding of energy transfer to justify why trolley W has the most likely velocity and why X, Y and Z do not.

[4]

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4a4 marks

A TV has the label below on it.

OCR TV

Voltage: 230 V
Power: 65 W
Frequency: 50 Hz

a)
Calculate the current in the TV when it is turned on.

Use the equation: power = potential difference × current

Give your answer to 2 significant figures.

Current = ...................................................... A [4]

4b4 marks
b)
The TV is turned on for 30 minutes.
Calculate the energy transferred by the TV.

Energy used = ...................................................... J [4]

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