Sound waves travel through water by:

D

Explanation:

Above the surface, the sound waves only vibrate your eardrum (unless the sound is very loud). When your head is submerged, your skull also vibrates with the sound because it is close to the same density and elasticity as water. Below the surface, sound waves pass directly through the water and into your head.

b. false

explanation:

suppose a rock in free fall is dropped off a cliff. after falling for 5 seconds, its speed would not be 100 m/s.