Question

A wheel rotating with an angular speed of $600rpm$ is given a constant acceleration of $1800rp{m}^2$ for $10sec$. The number of revolutions revolved by the wheel is.

• A. $125$
• B. $100$
• C. $75$
• D. $50$

Answer 1

The correct option is A

$125$

Step 1. Given data.

${\omega }_o=600rpm$

$\alpha =1800rp{m}^2$

$t=10sec=\frac{1}{6}min$

Step 2. Calculating number of revolutions

As given, ${\omega }_0$ is the angular speed of wheel rotating

$t$ is the time

$\alpha$is the constant acceleration

Therefore by using these variables, we have

$$\begin{gathered} S={\omega }_{o}t+\frac{1}{2}\alpha t^2 \\ =600\times \frac{10}{60}+\times \frac{1}{2}1800\times \frac{1}{36} \\ =100+25 \\ =125revolutions \end{gathered}$$

Hence, the correct option is (A).