A tennis player throws a .02 kg ball against the wall at 10m/s. It hits the wall and comes back at -17 m/s. His foot was in contact with the ball for .021 sec. What was the force of the kick? Remember what to do with two velocities.

fgravity=10x10=100n case 1

fgravity=30x20=600n case 2

6 times more

nah.   i'm just sleepy.

answer: the metamorphic rocks are formed when they are exposed to high pressure and high temperatures. this happens when one of the earth's plates comes in contact with the other plate by traveling in opposite directions, straight into each other or slipping under one another. the friction that is caused by this activity results in   melting of rocks and when it cools they are known as metamorphic rocks. this process needs a controlled amount of pressure and temperature otherwise it may turn into magma.