Question

Describe an activity to show that sound needs a material medium for its propagation

Answer 1

air is also medium
that's why we can say also we cannot hear sound in vacuum although light can travel in vacuum.
Liquid solid gas all have ability to propagate the sound cause they are media.

Answer 2

Answer:

Take a dry glass tumbler and place a cell phone in it, give a ring to this phone from another phone, then listen to the ring carefully. then surround the rim of the tumbler with your hands ,put your mouth on the opening between your hands ,give a ring again and listen to the ring while sucking the air from the tumbler ,you observe that loudness of the ring decreases, this is because when you suck air from the container the air is completely removed from it and it is said that there is vacuum in the vessel, so sound cannot travel through vacuum .therefore, sound needs a medium for propagation.

Explanation: