Question

The velocity of a particle moving on the x-axis is given by $v=x^2+x$ where v in m/s and x is in m. Its acceleration in $m/s^2$ when passing through the point x=2m.

• A. 0
• B. 5
• C. 11
• D. 30

Answer 1

Answer: (D)

30

$\begin{array}{c}v=x^2+x\\ \Rightarrow \frac{dv}{dx}=2x+1\\ \therefore a=\frac{vdv}{dx}\\ =\left(x^2+x\right)\left(2x+1\right)\\ \therefore atr=2\\ a=\left(4+2\right)\left(4+1\right)\\ =30m/s^2\end{array}$

$\therefore$ Option $D$ is correct answer.