When two bodies a heavy one and a light one are acted upon by the same...
This question is directly based on Newton's Third Law Of Motion.
Newton's Third Law of Motion states that "To every action, there is an equal and opposite reaction"
Hence, if one body applies a force F on another body, then simultaneously, the other body also exerts a force F on the first body.
Here, a heavier body collides with a lighter body. Both bodies exert the same amount of force on each other.
Suppose each body exerts a force F on the other.
By Newton's Second Law,
F = mxa
So, a = F/m
Here, Force F is the same on both bodies. But, as mass is different, their acceleration is different.
You can see that the larger body will have less acceleration, while the smaller body will have larger acceleration.
However, the fact remains that both bodies exert the same force on each other.