Question

Find the angular velocity of a body rotating with an acceleration of $2rev/s^2$ as it completes the 5th revolution with angular speed of

• A. $2rev/s$
• B. $2\sqrt{5}rev/s$
• C. $\sqrt{5}rev/s$
• D. $4\sqrt{5}rev/s$

Answer 1

The correct option is B $2\sqrt{5}rev/s$

Given in the question

We have $\theta =5$ revolutions

Angular velocity =$\omega =0$,

Acceleration $\alpha =2rev/s²$

Change in angluar velocity =${\omega }^{\prime }=?$

Now we know the formula

${{\omega }^{\prime }}^2={\omega }^2+2\alpha \theta$

${{\omega }^{\prime }}^2=0+2\ast 2\ast 5$

${\omega }^{\prime }=2\sqrt{5}rev/s$