Fig. 2 (b) .16 shows the time-acceleration graph for a particle in rectillinear motion. Find the averate acceleration in first twenty seconds.
.

Explanation

Average acceleration (a)
=(change in velocity)/(time taken)
:. Change in velocity
=average acceleration (x) time taken
=area of acceleration-time graph
:. Average acceleration
=(area of accleration-time graph )/(time taken )
`= (area fo acceleration-time graph0/(time taken)`
`=(area OABE) /(20) =(300)/(20) =15 ms^(-2)` .