Mechanics

New kid on the Block

Joined: 16 Mar 2012
Post: 1
16 Mar 2012 19:04:03 IST
1 People liked this
3
407 View Post
RIGID BODY DYNAMICS
Engineering Entrance , Medical Entrance , NEET , JEE Main , AIIMS , JEE Main & Advanced , Physics , Mechanics , Kinematics , NewtonsLawsCirMotion , Work Power Energy collisions , Rotation , Gravitation , Simple Harmonic Motion , Fluid Mechanics , Materials Wave Sound , Super Position , units dimensions , com momentum , shm , wave sound

 in any general problem of rigid body dynamics involving a pulley(when not considered light and has some inertia),we consider the tension on both the sides of ideal string to be different.....but when the string is ideal,it is considered to be massless,meaning thereby no gravitational force on it and no normal rkn force to the pulley....When the normal rkn force is zero,no frictional  force should  exist ....then how can tension be different????



Comments (3)


Scorching goIITian

Joined: 10 Feb 2012
Posts: 262
17 Mar 2012 14:55:24 IST
1 people liked this

It's not that way. According to the problem we know that for the blocks to move the pulley should rotate. Since the pulley is mass less there should be some external torque it should have to rotate. First just assume the tension to be equal and calculate the net torque you find that the pulley experiences zero torque i.e it won't rotate. now you are clear that the tension should be different. hoping you understand.If yes please like..
Viraat Gupta's Avatar

Forum Expert
Joined: 21 Jun 2011
Posts: 743
29 Mar 2012 21:14:13 IST
0 people liked this

just as said above , if the difference in tension occurs due to a nodal point , that is the pulley ... if there is no tension difference that means the mass at either side of the pulley is equal , hence no rotation of the pulley is possible
Viraat Gupta's Avatar

Forum Expert
Joined: 21 Jun 2011
Posts: 743
29 Mar 2012 21:14:47 IST
0 people liked this

just as said above , if the difference in tension occurs due to a nodal point , that is the pulley ... if there is no tension difference that means the mass at either side of the pulley is equal , hence no rotation of the pulley is possible



Quick Reply


Reply

Some HTML allowed.
Keep your comments above the belt or risk having them deleted.
Signup for a avatar to have your pictures show up by your comment
If Members see a thread that violates the Posting Rules, bring it to the attention of the Moderator Team
Free Sign Up!
Sponsored Ads

Preparing for JEE?

Kickstart your preparation with new improved study material - Books & Online Test Series for JEE 2014/ 2015


@ INR 5,443/-

For Quick Info

Name

Mobile

E-mail

City

Class

Vertical Limit

Top Contributors
All Time This Month Last Week
1. Bipin Dubey
Altitude - 16545 m
Post - 7958
2. Himanshu
Altitude - 10925 m
Post - 3836
3. Hari Shankar
Altitude - 10085 m
Post - 2217
4. edison
Altitude - 10825 m
Post - 7804
5. Sagar Saxena
Altitude - 8635 m
Post - 8064
6. Yagyadutt Mishr..
Altitude - 6330 m
Post - 1958

Find Posts by Topics

Physics

Topics

Mathematics

Chemistry

Biology

Parents Corner

Board

Fun Zone