Practical skills (OCR GCSE Physics A (Gateway)): Exam Questions

A student drops a paper ball from a balcony 4.00m high. Her friend measures the time taken for the paper ball to reach the ground.

Suggest the equipment used to measure the height of the balcony and the time taken for the paper ball to reach the ground.

Height .............................................................................................

Time taken .......................................................................................

They record their results in a table.

i) Use the data in the table to calculate the mean, median and mode of their results.

Mean = .................................................

Median = ..................................................

Mode = ...................................................

ii) The results are not very precise. Explain how you can tell from the data in the table.

iii) Suggest a possible source of error in the experimental method and how it could be improved.

Source of error ............................................................................... Improvement ...................................................................................

A student wants to investigate how a ball bounces.

He drops the ball from different heights and measures the bounce height each time.

He calculates the ratio bounce height / drop height.

The table shows his results.

The student predicts the ratio bounce height / drop height to be 1:1 when the drop height is 20 cm.

i) Suggest why he has made this prediction.

ii) Use ideas about energy to explain why this prediction cannot be correct.

Suggest two improvements to his experiment.

1 .......................................................................................................

2 .......................................................................................................

The mass of the ball is 60 grams.

i) Calculate the mass of the ball in kg.

Mass = ................................ kg

ii) Calculate the potential energy of the ball when it is 0.80 m above the ground.

Use your answer to (c)(i) and the equation:

potential energy = mass × height × gravitational field strength

Gravitational field strength = 10 N/kg

Potential energy = ................................ J

A student investigates the rate of cooling using a cardboard box to model the walls of a building.

She puts a beaker of hot water into the cardboard box. She measures the temperature of the water every two minutes.

She investigates how the rate of cooling changes with the thickness of the walls.

Describe a method she can use to do this investigation.

Here are the results of one of her experiments.

i) Plot the results on the grid in Fig. 17.1. Two of the points have been plotted for you.

ii) Draw a line of best fit on your graph.

Fig. 17.1

iii) Describe how the temperature of the water changes with time. Use data from the graph Fig. 17.1 in your answer

iv) The thickness of the cardboard box is doubled. Everything else stays the same.

Sketch a line on the graph in Fig. 17.1 to suggest what these new results may look like.

Label your line Z.

v) Suggest one way to improve the investigation.

Explain why the rate of cooling of a metal box is different to a cardboard box. Assume the thickness of the walls is the same in both boxes.

Two students investigate the resistance of a wire.

They tape a length of wire to a metre ruler and connect it to a resistance meter using crocodile clips.

Look at their results.

i) Describe the pattern shown by these results. Use data in your answer.

ii) The students made two mistakes when they recorded their results and completed the table.

Identify the mistakes and explain what they should have done.

iii) The students have correctly handled an anomaly in their results.

Identify the anomaly and explain how it was correctly handled.

iv) The students plan to plot a graph of mean resistance against length.

What would you expect a graph of these results to look like?

i) The actual mean resistance values are more than expected.

Suggest two possible errors with the experiment.

ii) For one of the errors, suggest how the experimental procedure could be improved.

Student A investigates how well different balls bounce.

• She drops five different balls from the same height and measures the height the ball bounce.

• She repeats the experiment three times for each ball.

Her results are shown in Table 20.1.

Table 20.1.

Student A forgot to record one of the bounce heights for the yellow ball in Table 20.1. Suggest the value of the missing result.

Answer ......................... cm

Student B does an experiment with bouncing balls.

• He does his experiment with a drop height of 200 cm.

• One ball bounces 100 cm.

Student B says that this ball is a better bouncer than any of Student As balls.

Use Table 20.1 and ideas about efficiency to explain why Student B is incorrect.

Student B uses a new ball. He says this ball is an amazing bouncer.

He says if you drop it from 200 cm it will bounce to a height of 250 cm.

Explain why this is not possible.