A gramophone record takes 5s to reach its constant angular velocity of 4\(\pi\) rads-1 from rest. Find its constant angular acceleration.
- 0.4\(\pi\) rads-2
-
0.8\(\pi\) rads-2
- 1.3\(\pi\) rads-2
- 20.0\(\pi\) rads-2
The correct answer is: B
Explanation
From the radiation:V = +at, and if it starts from N & T, U = 0
And for angular motion, W = O + at
4R = aχ5
∴ a = (4a)/5 = 0. 8\(\pi\) rads-2