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GCSE Questions - Forces

Q3. Clark watches a game of cricket on the school field.

He sees the ball being hit with a bat but he notices that he hears the sound a short time after.

This is because the speed of light is greater than the speed of sound. He decides to do an experiment to measure the speed of sound waves in air.

(a) Describe which measurements he needs to measure this speed.

He needs to measure the distance between the sound source and observer, which in this case will be the distance from himself to the batsman's position. He also needs to measure the time between seeing the bat hit by the bat and his hearing the 'thwak' of the ball making contact with the bat.

[2 marks]

(b) Which equation is used to calculate speed?

Speed = distance travelled/time taken

[1 mark]

(c) Describe how could get reliable results for this experiment.

Repeat the experiment, taking several readings at a range of distances. Then take averages of results.

Use distances that are as long as possible so that the time interval that has to be measured is as large as possible.

[2 marks]

(Total 5 marks)