Question

For how long should a force of $100N$ act on a body of $20kg$ so that is acquires a velocity of $100m{s}^{-1}$.

Answer 1

$a=\frac{F}{m}=\frac{100}{20}=5m/s^2$

$v=u+at$

$100=0+5\times t$

$\therefore t=\frac{100}{5}=20sec$