Question

A force $F_1$ acts on a particle, so as to accelerate it from rest to velocity $v$. If the force $F_1$ is replaced by $F_2$, which decelerates it to rest, then

• A. $F_1$ and $F_2$ must be zero
• B. $F_1$ must be equal $F_2$
• C. $F_1$ may be equal to $F_2$
• D. $F_1$ must not be equal to $F_2$

Answer 1

The correct option is C $F_1$ may be equal to $F_2$

When the body starts decelerating first,then$f_1$will not be equal to $f_2$,when the body finally comes to rest,$f_1$becomes equal to $f_2$.So. both the forces $may$ be equal.