Question

Action and reaction force acts on:
(A). Same body
(B). Different body
(C). Lower body
(D). Upper body

Answer 1

Hint: It is based on Newton's third law of motion where it is stated that force never occurs singly in nature force always occurs in pairs. Force is the mutual interaction between two bodies. Force between two bodies is nothing but action and reaction forces.

Complete step by step answer:
According to Newton’s third law of motion - “To every action, there is always an equal and opposite reaction.
i.e., If a body A exerts a force F on another body B, Then B exerts a force –F on A”
Consider a pair of bodies A and B, according to the third law.
${{F}_{AB}}=-{{F}_{BA}}$
(force on A by B) = - (force on B by A)
Thus, action and reaction forces act on different bodies, not on the same body so the correct option is B.
For example:
When we walk, we push ground backwards (action) instantly, ground pushes us forward(reaction) this action is by us on ground and reaction is on us by ground that it acted on different bodies with equal magnitude but opposite in direction.
We can give many examples like this in our day to day life we see -aeroplane moves forward pushing air backward swimmer swims forward by pushing water backward and rocket flying also an example of action and reaction forces acting on different bodies.

Note: Students may get confused and mark option A as they think it acts on a single body, but it is wrong force always occurs in pairs.
And there is a chance of marking option C by thinking intuitively that when mass, kept on the table it exerts force downward, so force acts only on the lower body. Similarly, by thinking that table exerts normal force on mass, so the answer may be on upper body and mark option D, but both are wrong.
If force acts only on the lower body that is mass only exerts force on the table (mg) then mass would have been moved downwards and if a force acts only on the upper body (on mass due to table- normal force) then mass would have been moved upwards but mass is at rest.
It is that, when mass is placed on the table, mass exerts force of mg downwards on the table (action) and table exerts normal force R upwards on the body (reaction) which are equal and opposite so cancels each other making body to be at rest.
Thus, action and reaction acts on different bodies.