# mechanics question rods with inextensible

Watch
Announcements
#1
I have done part a and do not understand how to start part B. can somebody give me some hints. Thanks
0
1 year ago
#2
Take moments about A. Friction must balance the COM
0
#3
0
#4
(Original post by mqb2766)
Take moments about A. Friction must balance the COM
What does COM mean?
0
1 year ago
#5
The moments due to the center of mass and friction must balance.
0
1 year ago
#6
(Original post by dasda)
I have done part a and do not understand how to start part B. can somebody give me some hints. Thanks
Draw a force diagram showing forces at the wall. Now the system is in equilibrium so what can we do?
0
#7
(Original post by Muttley79)
Draw a force diagram showing forces at the wall. Now the system is in equilibrium so what can we do?
Equate the vertical and horizontal forces to 0.
0
#8
I have drawn a diagram. Is this correct.

(Original post by Muttley79)
Draw a force diagram showing forces at the wall. Now the system is in equilibrium so what can we do?
0
1 year ago
#9
(Original post by dasda)
Equate the vertical and horizontal forces to 0.
You could also take moments ...
0
#10
(Original post by Muttley79)
You could also take moments ...
Ok i i wi try taking moments.
0
#11
is this correct
0
#12
(Original post by mqb2766)
The moments due to the center of mass and friction must balance.
For the force i got mg/2
0
1 year ago
#13
(Original post by dasda)
For the force i got mg/2
so how does that relate to the coeff of friction?
0
#14
0.5mg=ur. but i dont know what R is.

(Original post by mqb2766)
so how does that relate to the coeff of friction?
0
#15
the answer is 5/12 and I don't see how I will get to that answer.

(Original post by mqb2766)
so how does that relate to the coeff of friction?
0
1 year ago
#16
(Original post by dasda)
0.5mg=ur. but i dont know what R the is.
the reaction of the wall
The horizontal part of the tension
0
#17
(Original post by mqb2766)
the reaction of the wall
The horizontal part of the tension
but isn;t this in the direction of friction
0
#18
I am still not getting the same answer
0
1 year ago
#19
(Original post by dasda)
but isn;t this in the direction of friction
No, its perpendicular to the direction in which friction acts
0
1 year ago
#20
(Original post by dasda)
I am still not getting the same answer
Show working?
0
X

new posts
Back
to top
Latest
My Feed

### Oops, nobody has postedin the last few hours.

Why not re-start the conversation?

see more

### See more of what you like onThe Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

### Poll

Join the discussion

#### Do you have the space and resources you need to succeed in home learning?

Yes I have everything I need (188)
57.85%
I don't have everything I need (137)
42.15%