Find the average acceleration in first 20 s. (Hint: Area under a-t fraph is equal to the change in velocity). .

Find the average acceleration in first 20 s. (Hint: Area under a-t fra

1.	Find the average acceleration in first 20 s. (Hint: Area under a-t fraph is equal to the change in velocity). .
Answer» Solution :LET us first find the CHARGE in VELOCITY Change in velcity is the area under the ACCELERATION=time graph. For first `20 s`, Area `=Delta v (1)/(2) xx10 xx20+10xx20 =300 ms^(-1)` Average acceleration `=(Delta v)/(Delta t) =(300)/(20) =15 ms^(-2)`.