Question
Question: The paired action-reaction forces always act on _______ body(s). A. The same B. Different C. C...
The paired action-reaction forces always act on _______ body(s).
A. The same
B. Different
C. Curved
D. None of these
Solution
This question can be answered by using newton’s third law. According to Newton's third law for every action there will be an equal and opposite reaction. These action and reaction forces were called paired action – reaction forces in the question given.
Complete answer:
We will answer this by taking gravitational force as an example.
Gravitational force will be acting between any two masses at a particular distance. Since the magnitude of that force is very small nobody feels it. There are some similarities between the gravitational force and electrostatic force. gravitational force acts between the two masses whereas electrostatic force acts between the two charges. Both follow the inverse square law which means that the force will be inversely proportional to the square of distance between them.
So Newton discovered this gravitational force and due to this everybody on the earth is acted upon by the force due to the earth and this is what we call as the weight of the body.
We have the expression for the force between the earth of mass ‘M’ and the body of mass ‘m’ which are separated at the distance ‘r’ from the center of the earth. If we consider the surface of earth then r=R i.e radius of earth
That expression is
F=R2GMm
Where ‘G’ is the gravitational constant
So the force F is exerted by earth on mass m is considered as an action force while force having the same magnitude but opposite in direction is applied on earth by mass m and this is considered as reaction force. So action acts on mass ‘m’ while reaction acts on earth of mass ‘M’. so action reaction pairs act on different bodies.
Hence option B is the answer.
Note:
Basically there are four fundamental forces in nature. They are gravitational force, electrostatic force, strong nuclear force, weak nuclear force. Here the force in action is gravitational force and it is a long range force and the weakest of the four fundamental forces. While a strong nuclear force is the strongest of all.