A particle of mass 2 kg is initially at rest .A force acts on it whose magnitude change with time The force time graph is shown below .

The velocity of the particle after 10 s is

Options

A. A)`20ms^(-1)`
B. B)`10ms^(-1)`
C. C)`75ms^(-1)`
D. D)`50ms^(-1)`

Explanation

Area under the F-t curve = channge in momentum
or `(1)/(2)xx2xx(10)+2xx10+(1)/(2)(10+20)xx2`
`+(1)/(2)xx4xx20=m(v-u)`
or `10+20+30+40=2(v-0)`
or `100=2y`
or `v=50ms^(-1)`