Question

A body of mass $3kg$ is moving along a straight line with a velocity of $24{ms}^{-1}$. When it is at appoint ${}^{\prime }{P}^{\prime }$ a force of $9N$ acts on the body in a direction opposite to its motion. The time after which it will be at ${}^{\prime }{P}^{\prime }$ again is:

• A. $8s$
• B. $16s$
• C. $12s$
• D. $24s$

Answer 1

The correct option is B $16s$

F=ma

$9=3a$

$a=3m/s^2$

$v=u-at$

$0=24-3t$

t=8secs

Time after which it will be at P again is 2t=16s