Question

In Fig.

A. retardation is uniform
B. velocity is decreasing with time
C. beyond M, the body has negative velocity
D. all the above statements are correct.

Answer 1

We know that the change of velocity with time gives us the value of acceleration and when the curve of the velocity-time graph gives us the magnitude and nature of the acceleration that is whether it is negative or positive. We will use this concept to find the most suitable answer for our problem.

Complete step by step answer: From the given graph, we can see that the curve is negative, that means the velocity is decreasing as time progresses. Hence, option (B) is correct.

We also know that the value of velocity given by the straight line above the time axis is positive and it becomes zero at point M. Beyond point M, it becomes negative so we can say that velocity of the given body beyond point M is negative.
Hence option (C) is correct.

As we know that the acceleration is given by the curve of the velocity-time graph and the slope of the graph is negative. The slope of the velocity-time graph is given a straight line which means that the change of velocity with respect to time is constant. In other words, we can say that velocity change with time is constant, so the acceleration is uniform. Hence, option (A) is correct.

Therefore, from the above explanation, we can say that all the above statements are correct, and option (D) is correct.

Note: We know that the velocity is decreasing with time, so the acceleration is negative and called negative acceleration or retardation. Velocity becomes negative beyond point M, but acceleration is negative from the start, even at the point where velocity is positive.