# Forces - Section B - Practical questions

You will complete eight Practical Activity Groups (PAGs) if you are studying GCSE Physics, and 16 if you are studying GCSE Combined Science (six of these are in Physics). You could be asked questions about the apparatus, methods, safety precautions, results, analysis and evaluation of these experiments.

There are two PAGs in the Forces section:

• P2 Forces, eg investigate the effect of forces on springs
• P5 Motion, eg investigate acceleration of a trolley down a ramp

## Sample question 1 - Foundation

Question

Two students study the motion of a toy train on a track.

They need distance and time measurements to calculate speed.

Write down an instrument they could use to measure:

a) distance [1 mark]

b) time [1 mark]

OCR Gateway Science, GCE Physics, Paper J249, 2016.

a) Tape measure / ruler / metre rule

b) Stop clock / stop watch / timer

## Sample question 2 - Foundation

Question

A student set up the apparatus shown in the diagram.

Describe how they could use this apparatus to collect data to draw a force/extension graph for this spring. [4 marks]

OCR Gateway Science, GCE Physics, Paper J249, 2016.

Record the original length. Then, add a mass and record the new length. Repeat this process with larger masses.

## Sample question 3 - Higher

Question

A student investigates the motion of a glider on a frictionless air track. The student varies the force exerted on the glider, and measures its acceleration using a light gate connected to a data logger.

The table shows the results.

Force (N)Attempt 1 acceleration (m/s²)Attempt 2 acceleration (m/s²)Attempt 3 acceleration (m/s²)Attempt 4 acceleration (m/s²)
1.03.83.93.73.8
2.07.87.77.77.7
3.011.211.411.611.4
4.012.014.915.113.8
5.019.018.919.119.0

There is an anomaly in the results.

Identify the anomaly and explain how the student could have dealt with it. [1 mark]

OCR Gateway Science, GCE Physics, Paper J249, 2016 - Higher.

The anomaly is the 4 N/12.0 m/s2 result in Attempt 1. It should not be included in the mean, or the reading should be repeated.

## Sample question 4 - Higher

Question

A student researches potential and kinetic energy. She looks at some data from experiments with motion trolleys and energy.

The trolleys are stationary at the top of the 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.

TrolleyVelocity at the bottom of the ramp (m/s)
W3
X4
Y5
Z6

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 marks]

OCR Gateway Science, GCE Physics, Paper J249, 2016 - Higher.

The kinetic energy at the of the ramp must be equal to or less than the gravitational potential energy at the top of the ramp.

W: kinetic energy = 4.5 J. This result is reasonable because it is likely that some energy will be lost.

X: kinetic energy = 8.0 J. This result is possible but energy transfer is not 100% efficient so it is unlikely.

Y: kinetic energy = 12.5 J. This result is not possible because 12.5 J is more than the 8 J of gravitational potential energy the trolleys have at the top of the ramp.

Z: kinetic energy = 18 J. This result is not possible because 18 J is more than the 8 J of gravitational potential energy the trolleys have at the top of the ramp.