Waste less time on Facebook — follow Brilliant.

JEE mechanics doubt!! plz help

Q. If angular velocity of a disc depends on angle rotated \(\theta\) as \(\omega\) =\(\theta^{2}\) +\(2\theta\), then its angular acceleration \(\alpha\) at \(\theta\)=1 rad is

(1) 8 rad/\(sec^{2}\)
(2) 10 rad/\(sec^{2}\)
(3) 12 rad/\(sec^{2}\)
(4) None of these
The answer is (3) but i am not getting a solution so someone please help by providing one. Thanks!

Note by Akhilesh Chobey
3 years, 4 months ago

No vote yet
1 vote


Sort by:

Top Newest

since a(alpha) = dw/dt = (dw/ds )(ds/dt)=w(dw/ds).Hence ans will be 3*4=12

Piyush Bharti - 2 years ago

Log in to reply

i think angular acc is dw/dt to find that : first find dw/dtheta and then as we know w = dtheta/dt

so now take out inverse of w which is dt/dtheta and now divide dw/dtheta and dt/dtheta

Vaibhav Chaturvedi - 2 years, 2 months ago

Log in to reply

First differentiate omega with respect to t to get the expression of alpha then put the value of omega at theta 1 and theta

Vipra Goyal - 3 years ago

Log in to reply


Problem Loading...

Note Loading...

Set Loading...