The figure shows v−t graphs for various situations. What does that graph indicates

Hint: In the given figure we have given the velocity-time graph of two different cases. The Y-axis represents the velocity and the X-axis represents the time. We know that the slope of the velocity-time graph gives us acceleration. Therefore the two cases OA and BC represent two different accelerations. We can analyze each case and then we can find what OA & BC represent.

Complete Step By Step Answer:
As we said, the slope of the v-t graph gives us acceleration.
In the case of OA the slope is initially small and as it is going at the final stage slope is zero. Therefore we can say that acceleration is decreasing with time. Therefore OA represents decreasing acceleration
In the case of BC, it has a linear relationship. The angle of the slope is obtuse in the anti-clockwise direction with the X-axis and therefore we can say that the slope of the line is negative. And therefore BC represents negative acceleration.
Correct Answer:
OA – decreasing acceleration
BC – negative acceleration.

Note:
We already know that acceleration is the rate of change of velocity. If the velocity is increasing in the positive direction then this is called acceleration. If the velocity is decreasing in the negative direction then it is called deceleration. If the velocity is constant over a period of time then what will happen to the acceleration. If we calculate acceleration at different intervals of time then the acceleration at different intervals of time will be zero since there is no change in the velocity. But in the overall case, the acceleration is said to be uniform acceleration.