Question

A bullet is fired from a gun. The force on the bullet is given by $F=600-2\times {10}^{5}t$, where $F$ is in newtons and $t$ in seconds. The force on the bullet becomes zero as soon as it leaves the barrel. What is the average impulse imparted to the bullet?

• A. $9Ns$
• B. Zero
• C. $0.9Ns$
• D. $1.8Ns$

Answer 1

The correct option is C $0.9Ns$

Force at which time zero u

$F=0=600-2\times {10}^{5}tt=\frac{600}{2\times {10}^5}=3\times {10}^{-3}s$

Impulse imparted $={\int }_0^{t}Fdt$

$={\int }_0^t(600-2\times {10}^{5}t)dt={[600t-1\times {10}^5{t}^2]}_0^{3\times {10}^{-3}}=1.8-0.9=0.9Ns$