Question

If a force of 250 N act on a body, the momentum acquired is $125\,kg\,m\,s^{-1}$, what is the period for which force acts on the body ?

• A. 0.5s .
• B. 0.2s
• C. 0.4s
• D. 0.25s

Answer 1

Answer: (A)

0.5s .

Answer 2

Force = $\frac{Change \, in \, momentum}{Time}$ i.e. F = $\frac{\Delta p}{t}$ i.e. $t = \frac{\Delta p }{ F}$ $= \frac{125}{250}$ $= \frac{1}{2}$ $= 0.5\, s$ .