Experiments were done to investigate the effect of temperature on the speed of sound.
One person beat a drum while another person, who was standing 50 m away from the
sound source, recorded the time travelled by the sound.

They performed the experiment at different temperatures at different times of the day.
They recorded their findings in the table below.

7.1 For the investigation, write down the:
7.1.1 Investigative question (2)
7.1.2 Independent variable (1)
7.1.3 Dependent variable (1)
7.2 Calculate the speed of sound at 20 °C. (3)
7.3 Write down a conclusion for the investigation. (2)
The person who beat the drum, noticed that the sound reflected back after a while.
7.4 Name the term used to describe the reflection of sound waves. (1)
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