Question

The magnitude of force (in $N$) acting on a body varies with time $t$ (in $\mu s)$ as shown. $AB,BC$ and $CD$ are straight line segments. The magnitude of total impulse of force on the body from $t=4\mu s$ to $t=16\mu s$ is :

• A. ${10}^{-3}Ns$
• B. ${10}^{-2}Ns$
• C. ${10}^{-4}Ns$
• D. $5\times {10}^{-4}Ns$

Answer 1

The correct option is C ${10}^{-4}Ns$

The magnitude of impulse is area under the curve of $F-t$ diagram

$I=$ area from $4$ to $6\mu s+$ area from $6$ to $16\mu s$

$I=\frac{1}{2}(200+800)\times (6-4)+\frac{1}{2}\times 800\times (16-6)$

$I=1000+4000N\mu s$

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