The velocity- time graph of the particle moving along a straight line is shown. The rate of acceleration and deceleration is constant and it is equal to `5 ms^(-2)`. If the average velocity during the motion is `20 ms^(-1)`, then the value of t is

Options

A. `3` sec
B. `5` sec
C. `10` sec
D. `12` sec

Answer

B

Explanation

Average velocity
`=("Displacement")/("time interval")=("Area under v-t curve")/("time")`

`20=(1/2[25+25-2t]xx5t)/25rArr t=5, 20`