Question

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

• A. 6 × 10^-3Ns
• B. 3 × 10^-3Ns
• C. 5 × 10^-3Ns
• D. 6 × 10^-3Ns

Answer 1

Answer: (C)

5 × 10^-3Ns

Answer 2

Impulse = $\int_{}^{}{Fdt}$ = area under graph

∴ Total impulse from 4μs to 16 μs

= Area EBCD

= 1/2 (200 + 800)² × 10^-6 + $\frac{1}{2}$ X 800 × 10 × 10^-6

= 5 × 10^-3 Ns