Question
Physics Question on rotational motion
An athlete throws a discus from rest to a final angular velocity of 15rads−1 in 0.270s before releasing it. During acceleration, discus moves a circular arc of radius 0.810m. Acceleration of discus before it is released is
A
45ms−2
B
182ms−2
C
187ms−2
D
192ms−2
Answer
45ms−2
Explanation
Solution
Given, angular velocity, ω=15rad/s
Time, t=0.270s
Radius, r=0.810m
Acceleration, a=tv
or a=trω
[∵v=rω]
a=0.2700.810×15
=45m/s2