Question

Displacement - time graphs of a body in motion along a line is represented by four curves (a), (b), (c) and (d). Which of the curves indicated retardation motion?

Answer 1

Curve $\left(d\right)$ indicates retardation motion. Negative acceleration is called retardation. If the velocity of a body is decreasing with respect to time, the acceleration is said to be negative. Retardation is the rate of decrease in velocity. As seen from the graph the displacement in graph $\left(d\right)$ is decreasing with time which shows velocity is reducing.