I know this is impossible, but theoretically speaking what would happen if the moon was stopped, so that it stopped orbiting the earth and "stood still"? Would it hit earth or what impact would it have on earth?
If the moon momentarily stopped moving with respect to the Earth, then the Earth's gravity would pull the moon toward it. After a short time they would crash together. (It's likely that tidal forces would start pulling both the Earth and moon apart before they actually hit)
No. Think about which direction the moon would be moving. It would be gaining speed toward the earth, which would just cause it to keep coming. In order to go into a stable orbit, it would need to change direction and start moving parallel to the Earth's surface.
Is there anyway to calculate with what force the moon would hit earth and/or how long it would take? Or would such calculations be too complicated..? Is there in that case any simpler way to estimate the force and time?