Q 11-03-041NEETJEE MainEasy
A disc starts from rest and rotates with a uniform angular acceleration of $2\ \text{rad/s}^2$. The number of revolutions it makes in the first $10$ s is nearly
Answer: (B) $16$
Concept. From rest with uniform $\alpha$: $\theta = \dfrac12\alpha t^2$.
Step 1. Angle. $\theta = \dfrac12(2)(100) = 100$ rad.
Step 2. Revolutions. $\dfrac{100}{2\pi} \approx 15.9 \approx 16$.
Answer. $16$ (Option B).
Solution by Sreeraj P, M.Sc Physics