Question

a force of 10 Newton acts on a body for 3 microseconds calculate the impulse if mass of the body is 5 g calculate change of velocity

Answer 1

F=ma
F= mv/t
Mv= impulse
So impulse = f*t= 10 * 3 * 10^-6 = 3*10^-5 Ns

Now v = impulse/mass
V= (3*10^-5)/(5*10^-3)
= 3/500
= 0.006 m/s

Answer 2

$\bold{V=6 \times 10-3 \mathrm{m} / \mathrm{s}}$ is the change of  velocity.

Given:

Force = 10 Newton

Mass of the body = 5g

Time = 3 micro seconds

To find:

Change of velocity = ?

Solution:

$Force = mass \times acceleration$

And $acceleration =\frac{v e l o c i t y}{t i m e}$

$\mathrm{F}=\frac{m v}{t}$

We know force x time is impulse hence here impulse $= mv$

$Impulse =10 \times 3 \times 10^{-6}=3 \times 10^{-5} N s$

Now from the same formula impulse $= mv$

we get $v=\frac{i m p u l s e}{m}$

$\begin{aligned} \mathrm{V} &=\frac{\text {impulse}}{m}=\frac{3 \times 10^{-5}}{5 \times 10^{-3}} \\ V=& \frac{3}{5} \times 10^{-2}=6 \times 10^{-2} \end{aligned}$

$V=6 \times 10^-3 \mathrm{m} / \mathrm{s}$

Therefore, change of velocity $\bold{V=6 \times 10^-3 \mathrm{m} / \mathrm{s}}$.