1) A tennis ball is shot with an initial velocity of 10 m/s at an angle 60° Determine: a) the time it takes to hit the ground. b) max range, c) max height

The answer is frictional force

Ithink it's  c. i'm sure 

Sounds propagates through some kind of medium. usually it's air, but it goes just as well through solid objects like walls, windows etc. a soundwave will compress the (air)molecules in front of it, and if this increased density wave hits your ears, you register it as sound. solid objects like walls are a lot denser than air, this means that they will damp a wave, but also carry it easier.