Question

Angular displacement $(\theta)$ of a flywheel varies with time as $\theta = at + bt^{2} + ct^{3}$ then angular acceleration is given by

• A. $a + 2bt - 3ct^{2}$
• B. $2b - 6t$
• C. $a + 2b - 6t$
• D. $2b + 6ct$

Answer 1

Answer: (D)

$2b + 6ct$

Answer 2

Angular acceleration

$\alpha = \frac{d^{2}\theta}{dt^{2}} = \frac{d^{2}}{dt^{2}}(at + bt^{2} + ct^{3}) = 2b + 6ct$