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

Answer

`5s`

Explanation

`Vav = ("total distance travelled")/("time taken")`
`rArr Vav = ("area a convered by v-t dia. on time axis")/("time taken")`
`20 = ((1)/(2)(25 +25 -t)xx5t)/(25)`
`100 = (25-t)t rArr t^(2) - 25t +100 = 0`
`t = 5sec, t = 20 sec`.