A time varying force acts on a ball of mass 100g for 2ms . The...

As we know, impulse = area under F-t graph.

Therefore,

$\text{Impulse} = \dfrac{1}{2} \times \left(2 \times {10}^{- 3}\right) \times \left(20 \times {10}^{3}\right)$
$= 20kgm{s}^{- 1}$

Also, impulse is equal to change in momentum of the particle,

$∆ p = \text{impulse}$
$⇒ mv - mu = 20$
$⇒ v = \dfrac{20}{m} + u$
$= \dfrac{20}{0 . 1} + 10$
$= 210m{s}^{- 1}$