What do you think causes magnets to stick to a refrigerator? Why do other objects fall to the floor when placed in the same location?

# 1: Permanent magnets will attract any ferromagnetic material that is not already magnetized for repulsion.  There is an interesting reason for this that surprisingly is seldom taught in science courses that include magnetism as a subject. In these course students are usually simply told that with magnetism like poles repel and opposite poles attract. Since any refrigerator with ferromagnetic surfaces is not likely to be magnetically polarized at first, this doesn’t explain the attraction in this care or in most others.  Ferromagnetic materials contain usually microscopic regions called “magnetic domains:”  These are regions that have net magnetization. They are like tiny permanent magnets. Usually these domains are randomly oriented magnetically so that their overall magnetic effects almost completely cancel outside of whatever object they make up.  Bringing a permanent magnet near such an object causes the domains to change. Some grow in size while others shrink, and there can be small rotations of the magnetic orientations. The domains that grow are the ones with magnetic polarity opposite to that of the permanent magnet that is inducing the effects. This results in attraction. Also any rotations of domains are such as to produce attraction.  To simplify, the permanent magnet temporarily causes the nearer parts of the refrigerator surface to become magnetically polarized so that it acts like a magnet with the opposite pole closest to the nearest pole of the permanent magnet. Then opposite magnetic poles attract.

# 2: Gravity. The most remarkable and unexpected fact about falling objects is that, if air resistance and friction are negligible, then in a given location all objects fall toward the center of Earth with the same constant acceleration, independent of their mass.

c because the action was the roller coaster reaches bottom of hill (action) reaction would be blood tends to drain away from head

hope this !