Why are electromagnets used in metal scrap yards?

The image shows a pendulum in simple harmonic motion the pendulum starts at a and swing to e

Discuss how the hardness or softness of the landing surface is related to the time required to stop the egg

Ihave this 50 question test the layer of earth's atmosphere where atoms and molecules escape into space is referred to as the a) exosphere b) ionosphere. c) mesosphere d) thermosphere