Question

The angular velocity of a particle is given by

$\omega = 1.5\mspace{6mu} t - 3t^{2} + 2$, the time when its angular acceleration ceases to be zero will be

• A. $25\mspace{6mu}\sec$
• B. $0.25\mspace{6mu}\sec$
• C. $12\mspace{6mu}\sec$
• D. $1.2\mspace{6mu}\sec$

Answer 1

Answer: (B)

$0.25\mspace{6mu}\sec$

Answer 2

$\omega = 1.5t - 3t^{2} + 2$ and $\alpha = \frac{d\omega}{dt} = 1.5 - 6t$

$\Rightarrow 0 = 1.5 - 6t\therefore t = \frac{1.5}{6} = 0.25\sec$