A gramophone record takes 5s to reach its constant angular velocity of 4\(\pi\) rads-1 from rest. Find its constant angular acceleration.
A
0.4\(\pi\) rads-2
B
0.8\(\pi\) rads-2
C
1.3\(\pi\) rads-2
D
20.0\(\pi\) rads-2
Verified Correct Answer: B.
Physical Principles & Numerical Solution
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
Source: Myschool Past Questions Archive (Record #13903)