Thank you for registering.

One of our academic counsellors will contact you within 1 working day.

Please check your email for login details.
MY CART (5)

Use Coupon: CART20 and get 20% off on all online Study Material

ITEM
DETAILS
MRP
DISCOUNT
FINAL PRICE
Total Price: Rs.

There are no items in this cart.
Continue Shopping

http://www.askiitians.com/forums/Mechanics/10/53951/Dynamics.htm

http://www.askiitians.com/forums/Mechanics/10/53951/Dynamics.htm

Grade:12

1 Answers

Aman Bansal
592 Points
8 years ago

Dear Anurag,

Method I: Torque and Angular Acceleration
Choose the origin for calculating torques and angular momentum as the pivot point of thependulum, and let ! be the angular displacement of the pendulum string from thevertical. The only forces on the pendulum are the gravitational force on the pendulumbob (the pointlike object) and the tension in the string. With respect to the pivot, thetension exerts no torque. The moment arm for the gravitational torque is r" = l sin ! , fora net torque
! net = #mgl sin " .
The minus sign in Equation (1.1) is crucial; the torque will act to restore the angle ! toits equilibrium value ! = 0 . If ! > 0 , ! net < 0 and if ! < 0 , ! net > 0 (this assumes thatthe angle ! is restricted to the range #! < " < ! , implied by the small-angleapproximation sin ! 0 ! ! 0 ).
With the assumption of a massless string, the moment of inertia about the pivot point is
I pivot = ml 2 .
The angular acceleration ! is related kinematically to the displacement angle ! by
d 2!.dt 2
"=
The torque, moment of inertia and angular acceleration are related by
! net = I pivot " .
Combining Equations (1.1), (1.2), (1.3) and (1.4) yields the answer.

Cracking IIT just got more exciting,It s not just all about getting assistance from IITians, alongside Target Achievement and Rewards play an important role. ASKIITIANS has it all for you, wherein you get assistance only from IITians for your preparation and win by answering queries in the discussion forums. Reward points 5 + 15 for all those who upload their pic and download the ASKIITIANS Toolbar, just a simple  to download the toolbar….

So start the brain storming…. become a leader with Elite Expert League ASKIITIANS

Thanks

Aman Bansal

Askiitian Expert

Think You Can Provide A Better Answer ?

Provide a better Answer & Earn Cool Goodies See our forum point policy

ASK QUESTION

Get your questions answered by the expert for free