KS3 Questions on Sound

Q4.

(a) When people speak, sounds are made by their vocal cords. How do the vocal cords make a sound?

They vibrate

1 mark

(b) The astronauts who landed on the Moon had to wear spacesuits. The spacesuits were filled with air because there is a vacuum on the Moon.

(i) The astronauts had radios in their helmets. Without the radios, they could not hear each other speaking. Why does sound not travel on the Moon?

There is no air or atmosphere on the Moon and sound cannot travel through a vacuum (as it needs to pass energy on by vibration of particles).

1 mark

(ii) If the radios broke, the astronauts could put their helmets together so that they touched. Then they could hear each other's voices. Why could they hear each other's voices when their helmets were touching?

The sound can travel from one helmet to the other without passing through a vacuum. The helmets pass on the vibrations from each other.

MAX 1 mark

Total 3 marks