| Author |
Message |
![[Post New]](/templates/default/images/icon_minipost_new.gif) 3 May 2008 21:34:15 IST
|
|
|
A CUBICAL BLOC OF MASS M AND EDGE a SLIDES DOWN ON A ROUGH INCLINATION PLANE OF ANGLE @ WITH UNIFORM SPEED. FIND THE MAGNITUDE OF THE TORQUE OF THE NORMAL FORCE ACTING ON THE BLOCK ABOUT ITS CENTRE
ANS 1/2MGASIN@
MY DOUBT IS THAT SINCE THE NORMAL FORCE INTERSECTS THE CENTRE ITS TORQUE SHOULD BE 0
MG COS @ IS ALSO INTERSECTING THE CENTRE SO THE TORQUE AGAIN WILL BE 0
THE ONLY FORCE WHICH IS LEFT IS MGSIN@ AND ITS DISTANCE FROM THE CENTRE IS a/2 SO
THE TORQUE CAN BE 1/2 MGIN@
BUT MGSIN@ IS NOT THE NORMAL FORCE PLS EXPLN
|
From shadows a light shall spring
Renewed shall be blade that's broken
The crown less again shall be king.
|
|
|
|
3 May 2008 23:12:25 IST
|
|
|
PLS EXPLN
|
From shadows a light shall spring
Renewed shall be blade that's broken
The crown less again shall be king.
|
this reply: 0 points
(with 0 
in 0 votes ) [?]
|
|
You have to be logged on to rate
|
|
|
3 May 2008 23:18:53 IST
|
|
|
i think the torque is due to the frictional force and not the component of weight.
frictional force acts in a direction exactly opposite to the direction of motion and the magnitude will be exactly equal to the component of weight in that direction ie mgsin@
i said it is equal in magnitude since the resultant force should be zero as the cube moves with a uniform speed.
so a force of mgsin@ acts at a distance a/2 from centre of mass.
thus the given torque.
also there is friction since it is a rough plane.
do rate me if it this explanation is useful
|
Who shoots at the midday sun though he be sure that he will not get the mark:yet as sure he is that he shall shoot higher than who aims but at a bush. |
this reply: 0 points
(with 0
in 0 votes ) [?]
|
|
You have to be logged on to rate
|
|
|
3 May 2008 23:34:30 IST
|
|
|
but the QUESTION IS ASKING
THE TORQE OF THE NORMAL FORCE
|
From shadows a light shall spring
Renewed shall be blade that's broken
The crown less again shall be king.
|
this reply: 0 points
(with 0
in 0 votes ) [?]
|
|
You have to be logged on to rate
|
|
|
3 May 2008 23:37:38 IST
|
|
|
the normal force can anyway cause no turning effect.
so torque due to that will be 0 for sure.
what i said was the net torque acting on it.
|
Who shoots at the midday sun though he be sure that he will not get the mark:yet as sure he is that he shall shoot higher than who aims but at a bush. |
this reply: 0 points
(with 0
in 0 votes ) [?]
|
|
You have to be logged on to rate
|
|
|
3 May 2008 23:39:04 IST
|
|
|
THE NET TORQUE IS 1/2MGASIN@
I KNOW BUT HTE QUES IS ACTING THE TORQUE OF THE
NORMAL FORCE
HCV SUM NO 21
PG 196
|
From shadows a light shall spring
Renewed shall be blade that's broken
The crown less again shall be king.
|
this reply: 0 points
(with 0
in 0 votes ) [?]
|
|
You have to be logged on to rate
|
|
|
3 May 2008 23:40:59 IST
|
|
|
anyway the frictional force is due to the normal rection or normal force and might be we need to take in that manner.
|
Who shoots at the midday sun though he be sure that he will not get the mark:yet as sure he is that he shall shoot higher than who aims but at a bush. |
this reply: 0 points
(with 0
in 0 votes ) [?]
|
|
You have to be logged on to rate
|
|
|
3 May 2008 23:41:32 IST
|
|
|
can anyone else post their explanation in this regard?
|
Who shoots at the midday sun though he be sure that he will not get the mark:yet as sure he is that he shall shoot higher than who aims but at a bush. |
this reply: 0 points
(with 0
in 0 votes ) [?]
|
|
You have to be logged on to rate
|
|
|
4 May 2008 08:45:14 IST
|
|
|
PLS MORE REPLIES
|
From shadows a light shall spring
Renewed shall be blade that's broken
The crown less again shall be king.
|
this reply: 0 points
(with 0
in 0 votes ) [?]
|
|
You have to be logged on to rate
|
|
|
4 May 2008 09:29:09 IST
|
|
|
more replies
|
From shadows a light shall spring
Renewed shall be blade that's broken
The crown less again shall be king.
|
this reply: 0 points
(with 0
in 0 votes ) [?]
|
|
You have to be logged on to rate
|
|
|
4 May 2008 10:29:55 IST
|
|
|
DUDES WHAT HAPPENED
|
From shadows a light shall spring
Renewed shall be blade that's broken
The crown less again shall be king.
|
this reply: 0 points
(with 0
in 0 votes ) [?]
|
|
You have to be logged on to rate
|
|
|
4 May 2008 11:24:26 IST
|
|
|
Who says normal force can't cause any turning effect....?
|
this reply: 0 points
(with 0
in 0 votes ) [?]
|
|
You have to be logged on to rate
|
|
|
4 May 2008 11:26:46 IST
|
|
|
BUT IT INTERSECTS THE AXIS
|
From shadows a light shall spring
Renewed shall be blade that's broken
The crown less again shall be king.
|
this reply: 0 points
(with 0
in 0 votes ) [?]
|
|
You have to be logged on to rate
|
|
|
4 May 2008 11:27:01 IST
|
|
|
It all depends on the instantaneous axis of rotation..... I haven't really understood the question... but you can work it out very easily.... this is just one of those cases of blocks toppling on inclined planes....
take the axis of rotation to be one passing through the lowermost edge of the block... I can't really draw it right now.. but you can easily understand....... the edge that is at the lowest point....... take it to be the axis of rotation
|
this reply: 0 points
(with 0
in 0 votes ) [?]
|
|
You have to be logged on to rate
|
|
|
4 May 2008 11:29:15 IST
|
|
|
Friction force then has no Torque... gravitational for |
Moderation Team
![[Up]](/templates/default/images/icon_up.gif "[Up]"){kind=icon}
