Question

If the displacement of a particle moving in straight line is given by $x=3t^2+2t+1$ at time $t$ then the acceleration of the particle at time $t=3$ is

• A. $6$
• B. $3$
• C. $9$
• D. none of these

Answer 1

Answer: (A)

$6$

Given the displacement of a particle moving in straight line is given by $x=3t^2+2t+1$.......(1) at time $t$.

Now acceleration is given by $\frac{d^{2}x}{d{t}^2}$.

From (1) we have

$\frac{dx}{dt}=6t+2$

And $\frac{d^{2}x}{d{t}^2}=6$, which is independent of $t$.

So at time $t=3$ the acceleration will be $6$.