Give scientific reasons.

Even though the magnitudes of action force and reaction force are equal and their directions are opposite, their effects do not get cancelled.

i. When the point of action of the two equal and opposite forces is the same, then these do cancel out.

ii. But when the point of action of the two equal and opposite forces is different Though it located on the same body but separated by some distance between a the points of action of the two forces, then these forces don’t cancel out, but rather produce a couple. Example, closing a tap.

iii. But, if they are acting on different bodies, they cannot cancel out but rather produce motion.

For example, the downward weight is cancelled by the normal force while the force of the sun on the earth and its reaction, the force of the earth on the sun, do not cancel each other. We can see from diagram also.