A particle of mass 2 kg is initially at rest. A force , acts on it whose magnitude changes with time. The force-time graph is of shown here.
The velocity of the particle after 10 s is

Options

A. `20 ms^(-1)`
B. `10 ms^(-1)`
C. `75 ms^(-1)`
D. `26 ms^(-1)`

Answer

D

Explanation

Change in momentum = Impulse = area under F – t graph
`rArr mv =(1)/(2) xx 2 xx 10 + 2 xx 10 + (1)/(2) xx 2(10+20) + (1)/(2) 44 xx 20 `
` = 10 + 20 + 30 + 40 = 100`
`v =(100)/(2) = 50 m//s`