Q.
An object is moving in positive direction till time t and then turns back with the same negative acceleration. The velocity time graph which best describes the situation is:
Here, we observe that the object is moving in positive direction till time t=0 to t=t1 and at t=t1 we find that the velocity become negative i.e., the object changes its direction at t=t1 and continues in negative direction hence forth. For acceleration we can observe that throughtout the journey the slope of the v-t curve is negative and hence, acceleration is negative. Thus, the area under the v−t curve gives displacement.