Join the Most Relevant JEE Main 2025 Test Series & get 99+ percentile! Join Now
Search any question & find its solution
Question: Answered & Verified by Expert
A rotating wheel changes angular speed from \( 1800 \mathrm{rpm} \) to \( 3000 \mathrm{rpm} \) in \( 20 \mathrm{~s} \). What is the
angular acceleration assuming to be uniform ?
PhysicsLaws of MotionKCETKCET 2014
Options:
  • A \( 60 \) п rad s \( ^{-2} \)
  • B 90п rad s \( ^{-2} \)
  • C \( 2 \Pi \mathrm{rad} s^{-2} \)
  • D 40п rad s \( ^{-2} \)
Solution:
2095 Upvotes Verified Answer
The correct answer is: \( 2 \Pi \mathrm{rad} s^{-2} \)
For angular speed of \( 1800 \mathrm{rpm} \)
\( \omega_{1}=2 \Pi f_{1}=2 \Pi\left(\frac{1800}{60}\right)=60 \Pi \mathrm{rad} s^{-1} \)
For angular speed of \( 3000 \mathrm{rpm} \)
\( \omega_{2}=2 \Pi f_{2}=2 \Pi\left(\frac{3000}{60}\right)=100 \Pi \mathrm{rad} s^{-1} \)
Therefore, angular acceleration \( =\frac{\omega_{2}-\omega_{1}}{t}=\frac{100 \Pi-60 \Pi}{20} \)
\( =\frac{40 \Pi}{20}=2 \Pi \)
Thus, angular acceleration of rotating wheel \( =2 \pi \mathrm{rads}^{-2} \)

Looking for more such questions to practice?

Download the MARKS App - The ultimate prep app for IIT JEE & NEET with chapter-wise PYQs, revision notes, formula sheets, custom tests & much more.