A short-cut is to think about a couple who are in love or quarrel. When in love, both are walking together in one direction holding hand (i.e. current in both wires are in same direction ). Hence there is ATTRACTION between them. When the couple quarrel, both are walking in opposite direction (i.e. c urrent in opposite direction ). Hence there is REPULSION between them.

In this post, it shows a free-falling ball from a height of 1.0 m. During the impact, the direction of the force on the ground is downwards and the force on the ground by the ball is greater then the weight. As the ball is free-falling, the only force acting is its weight downwards. Hence a common misconception is to think that the force on the ground during impact is equal to the weight. This is wrong. The normal force (force on the ball by the ground = stopping force on the ball by the ground) is greater than the weight . The force on the ball by the ground is equal and opposite to the force on the ground by the ball . Hence the magnitude of the force on the ground is greater than the weight . Similar concept can be applied if a man jumps off from a height. But in this case, the man’s leg will exert a stopping force over a short distance. That stopping force, once again, is greater than the weight of the man.