The displacement-time graph of a particle moving along a straight line is drawn below. The accelerations of the particle during the regions OP, PQ and QR are

Options

A. OP = -, PQ = 0, QR = +
B. OP = +, PQ = 0, QR = +
C. OP = +, PQ = 0, QR = -
D. OP = -, PQ = 0, QR = -

Answer

C

Explanation

Acceleration `= (d^(2)x)/(d t^(2))`
For part OP, the acceleration is positive as the velocity is increasing, slope is increasing. For part PQ, the acceleration is zero. Horizontal straight line shows that the velocity is zero. For part QR, acceleration is negative. It is retarded motion. Velocity is decreasing as the slop decreases with time.