The acceleration-time graph of a particle moving along a straight line is as shown in. At what time the particle acquires its initial velocity?
.

Options

A. 12 sec
B. 5 sec
C. 8 sec
D. 16 sec

Answer

C

Explanation

Upward area of a a-t graph gives the change in velocity `=20 m//s` for acquiring initial velocity, it again charges by same amount in negative direction.
Slope of curve`=-10//4=-2.5`

`:.` time `=sqrt((2xx20)/(2.5))=4` sec
Total time`=4+4=8` sec