d.) a and b only
This is because sound needs a medium to travel. It can travel in a solid (the fastest) and air for example. Sound waves cannot propagate through a vacuum and since space is a vacuum the answer is a and b only.
If the billiard ball is going at the constant speed and contains its mass then the momentum WONT be changing. But realistically you have external forces like friction and air resistance changing the velocity thus changing the momentum. In this case momentum is not conserved because you're introduction an external force.
The longer the lever the longer the power
As depth increases underwater, colors disappear due to water's ability to ... takes a diver one hour to breath all the air from a scuba tank at the surface, ...
W=mg
W=75(1.6)
W=120N
a. 120N
