## akhil009 3 years ago torque and moment i am really confused b/w these 2 help me out here guyz . another thing when to use which method for direction ? 1. right hand screw rule 2. vector cross product rule it turns out apply both the direction will not be same why ?(ref. a simple beam and a point load acting on transverse plane)

1. rajathsbhat

both 'torque' & 'moment of force' mean the same thing. As for the second question, all these rules are equivalent---meaning that , regardless of which rule you use, you will get the same direction. It's just a matter of choice, really.

2. rajathsbhat

Any questions?

3. akhil009

for simply supported beam a point load is acting then how do u calculate direction n which method

4. akhil009

by vector cross product rule we have force in -j n distance +i resultant cross product will give k direction means beam will tend to rotate in k hows that possible ?

5. rajathsbhat

|dw:1343126765977:dw| So what is your doubt?

6. akhil009

yes thats right moment will act in k direction n tend to rotate in same but in actual when u apply point load on beam it will tries to rotate in xy plane

7. akhil009

|dw:1343127230930:dw|

8. akhil009

|dw:1343127366588:dw|

9. rajathsbhat

Now, I get it. You think that if the direction of the torque is in the k direction, then it has to rotate in that direction. Am I right?

10. akhil009

yes exactly

11. rajathsbhat

That is where you are mistaken. This needs a long explanation. Can you wait for about 20 minutes while I write & explain to you what the direction of torque means- in paper & upload it?

12. akhil009

thanks for ur help i appreciate it yes why wouldnt i wait

13. akhil009

i will wait thanks in advance

14. rajathsbhat

are you in some kind of a hurry? I ask this because paper just won't do. You cannot explain directions in 3D with them. So I thought I'd make a short video to explain it. It may take me 2 hrs to upload it.

15. rajathsbhat

so is that a yes?

16. akhil009

no i am not in any hurry

17. rajathsbhat

Great. I'll get to work, then. :) I'll post a link here ASAP okay?

18. akhil009

yeah ok

19. akhil009

@rajath dont worry i got the answer to that, see the direction which comes out to be k is direction of normal vector or u can say that axis about which it will rotate its not the sense of rotation

20. rajathsbhat

that's absolutely right, @akhil009, congrats!! :)