A bullet is fired from a gun. The force on the bullet is given by `F=600-2xx10^(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?

Options

A. 1.8 N-s
B. Zero
C. 9 N-s
D. 0.9 N-s

Answer

D

Explanation

Given `F=600-2xx10^(5)t`
The force is zero at time t, given by
`0=600-2xx10^(5) t`
`rArr t=(600)/(2xx10^(5))=3xx10^(-3)` seconds
`:.` Impulse `= int_(0)^(t) Fdt= int_(0)^(3xx10^(-3)) (600-2xx10^(5)t)dt`
`[600t-(2xx10^(5)t^(2))/(2)]_(0)^(3xx10^(-3))=0.9Ns`