Question

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

• A. 1.8 N
• B. zero
• C. 9 N
• D. 0.9N

Answer 1

Answer: (B)

The force is given by $F=600-2\times {10}^{5}t=0$ So, time for which force acts is $t=\frac{600}{2\times {10}^5}$ $=3\times {10}^{-3}\sec$ $\therefore$ Average impulse $\text{= force }\times \text{ time}$ $=(600-2\times {10}^5\times 3\times {10}^{-3})$ $=0$