Question

Do action and reaction act on the same body or different bodies? How are they related in magnitude and direction? Are they simultaneous or not?

Answer 1

Hint:Force is a quantity which can be observed anytime anywhere. For example, when you push or pull a box which is kept on a floor, you say that you have applied a force on the box in order to move it. The study of force can be done on the basis of Newton’s Laws of motion. In order to solve this question, consider Newton's third law of motion.

Complete answer:
There are three laws of motion given by Newton. The first one is “A body will remain at rest until a force is applied on the body”. The second law gives the relation between force, mass and acceleration. The third law states that, when a body A applies a force on another body B, this body B applies equal and opposite force on the body A. As you can see that, when body A applies force on body B, the body B reacts and in reaction it applies force on body A.

This tells you that the action and reaction acts on different bodies. According to the third law, the reacting force is equal in magnitude of the acting force and the direction of the reacting force is opposite to that of the acting force. The reacting force is a responsive force, so it will act simultaneously with the acting force and will keep on acting until the applied/acting force is removed.

Hence, action and reaction act on different bodies, the reaction force is equal and opposite to the applied force and they act simultaneously.

Note:Remember that the third law tells you that when a force is applied by an object A on object B, the object B will apply an equal and opposite force on object A simultaneously and will keep on applying until the object A stops applying force. Always keep in mind the three laws of motion, these laws can be used to solve any question in mechanics.