# Kindly help me solve Question number 76. Thank you in advance.

Solution
We know that acceleration is equal to the derivative of velocity with respect to time. So, the velocity can be obtained by taking the time integral of acceleration.
a=dv/dt

Therefore, we need to study the area under the curve for the acceleration-time graph in order to obtain the velocity time graph.
Consider the given plot for acceleration and time.

We can make the following observations for the area under the curve which represents the variation of velocity with time.
1. As we go from O to a that is first rectangle, we notice that the area under the curve goes on increasing linearly. Therefore, from O to a, the velocity increases linearly.
2. At the area becomes zero and stays zero upto b that is till start of second rectangle. This means that acceleration is zero and corresponding to it the velocity will remain constant.
3. From b, the area starts increasing and beyond b, the area increases linearly just like the first case. So, after point b, the velocity increases linearly.
Based on these observations, we can have the following variation of velocity with time.

Based on this, the correct answer to the question is option A.

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