statics problem

[pongo22]

hi there, i need help. please see attachment.
I managed to work most of the questions but just need a quick check
-i would also like to confirm that there is two force diagram with no change in friction.
-f(i) i need help to show that, 'M is greater or equal to mtanα', cant seem to get my head around this.
- i would also like to check that the angle value for (g) is less or equal to arctan (M/m)

regards

kevin

 

[Deleted member 4993]

hi there, i need help. please see attachment.
I managed to work most of the questions but just need a quick check
-i would also like to confirm that there is two force diagram with no change in friction.
-f(i) i need help to show that, 'M is greater or equal to mtanα', cant seem to get my head around this.
- i would also like to check that the angle value for (g) is less or equal to arctan (M/m)

regards

kevin

For us to check your work - we need to see your work. Please post those.

 

[pongo22]

For us to check your work - we need to see your work. Please post those.

we need to consider the two causes of possible movement.

the first case is where, 'm' is likely to drop down and pull 'M' down the rough plane.
the force diagram is as follows


define the forces t1,t2,w1,w2,f,n.

this is where am stuck on whether the second condition when the mass M rolls downward and pull m upward if the force diagram changes.

thank you

 

[Deleted member 4993]

we need to consider the two causes of possible movement.

the first case is where, 'm' is likely to drop down and pull 'M' down the rough plane.
the force diagram is as follows

View attachment 2525
define the forces t1,t2,w1,w2,f,n.

this is where am stuck on whether the second condition when the mass M rolls downward and pull m upward if the force diagram changes.

thank you

For your case#1 (where the impending motion for M is pointing down the slope) - which way should the frictional force (between M and the surface) act?

For your case #2 - when the mass M rolls downward and pull m upward - to pull m upward, the length of the string Between M and the pulley must increase. When can that happen?