Question

The displacement-time graph of a particle moving along a straight line is shown in the figure.

The acceleration-time graph of this particle is

• A.
• B.
• C.
• D.

Answer 1

Answer: (B)

Given, $x=9t^2$
$\therefore v=\frac{dx}{dt}=\frac{d}{dt}\left(9t^2\right)=\frac{9d}{dt}\left(t^2\right)=18t$
also, $a=\frac{d^{2}x}{d{t}^2}=\frac{dv}{dt}=\frac{d}{dt}(18t)=18$
So, the graph between acceleration and time is a line parallel to time axis as acceleration is constant.