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. 9 Ns
B. Zero
C. 0.9 Ns
D. 1.8 Ns

Answer

C

Explanation

`F = 600- 2 xx 10^(-5)t`
`F = 0 rArr t = (600)/( 2 xx 10^(5)) = 3 xx 10^(-3)` sec.
Impulse `(I) = int_(0)^(t) =F dt = int_(0)^(3 xx 10^(-3)) (600 - 2 xx 10^(5) t) dt`
` =[600 t - 10^(5)t^(2)]_(0)^(3 xx 10^(-3))`
` [ {(3 xx 10^(-3) xx 600 - 10^(5) (3xx 10^(-3))^(2)} -0]`
` = 0.9` Ns.