Question

The velocity time graph of a particle moving along a straight line has the form of a parabola $t^2-6t+8$ m/s. Find the velocity (in m/s) when acceleration of particle is zero :

• A. $-1$
• B. $-2$
• C. $-3$
• D. $-4$

Answer 1

Answer: (A)

$-1$

Here, velocity $v=t^2-6t+8$

So, acceleration, $a=\frac{dv}{dt}=2t-6$

When acceleration is zero, $2t-6=0$ or $t=3$

and the veclocity will be $v(t=3)=3^2-6\left(3\right)+8=9-18+8=-1m/s$