The acceleration-time graph of a particle moving in a straight line is as shown in figure. The velocity of the particle at time `t = 0` is `2 m//s`. The velocity after `2` seconds will be

Options

A. `6 m//s`
B. `4 m//s`
C. `2 m//s`
D. `8 m//s`

Answer

A

Explanation

Area under `a - t` graph gives the change in velocity
`(dv = a dt)`
`v_f = v_i = (1)/(2) xx 2 xx 4 = 4 m//s`
`v_f = v_i + 4 = 2 + 4 = 6 m//s`.