Question

A force of $50dynes$ is acted on a body of mass $5g$ which is at rest for an interval of $3$ seconds, then impulse is (in $Ns$):

• A. $1.5\times {10}^{-}3$
• B. $1.5\times {10}^{-}2$
• C. $2.5\times {10}^{-}3$
• D. $1.5\times {10}^3$

Answer 1

Answer: (A)

$1.5\times {10}^{-}3$

Force acting on the body $F=50dynes=50\times {10}^{-5}N$

Time of action of force $t=3s$

Thus impulse $I=Ft$

$\therefore I=50\times {10}^{-5}\times 3=1.5\times {10}^{-3}Ns$