Which is true of a mechanical wave?

a) it must have a medium.

b) it must travel in empty space.

c) both sound and light are examples.

d) it can travel in a vacuum.

A) True

Mechanical waves need a medium to travel.

B) False.

Mechanical waves need a medium to travel. So they can not travel in empty space.

C) False

Sound is a mechanical wave since it needs a medium to travel. light wave is electromagnetic wave and it can travel in empty space too.

D) False

Mechanical waves need a medium to travel. So they can not travel in empty space.

the answer is false. this is because for ice to melt, it requires latent heat of melting. latent heat means heat energy required to change phase without any increase in temperatures. therefore, the ice will take energy from the environment to melt hence atmospheric temperatures will reduce.