What should be the free body diagram?

AI Thread Summary
The discussion focuses on analyzing the forces acting on two blocks, M1 and M2, in a system with given masses and friction coefficients. M1 experiences a rightward force (F) and leftward friction, while M2 experiences rightward friction and forces from the pulleys. The tension in the rope is assumed to be equal to F, with the upper pulley experiencing forces downward and to the left. The lower pulley exerts a rightward force on M2, but the net force on M2 from the rope is zero when considering the friction between the blocks. The analysis concludes that only the frictional reaction between M1 and M2 influences M2's movement horizontally.
AlchemistK
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Homework Statement


The Question gives some data, and a figure to find out the acceleration.
In the arrangement shown (refer attachment) shown, M1=20kg, M2=30Kg, floor is smooth and friction between two blocks: μ(s) = 0.6, μ(k) = 0.4.
F= 400N
What are the forces acting on the two blocks?

Homework Equations


The Attempt at a Solution


On M1, there is F acting towards right, and the friction towards the left.
For M2, There is the friction acting towards right, and then the forces exerted by the pulleys.
In what direction and magnitude do they act?
 

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I'm assuming the pulleys are frictionless and have negligible mass.

Then the tension in the rope in all locations is F .

Forces exerted on the upper pulley: The rope exerts a force (equal to F) downward and a force, F to the left.

Forces exerted on the lower pulley: What do you think?

The pulleys may be considered as part of Block 1 .

https://www.physicsforums.com/attachment.php?attachmentid=40217&d=1319254345
 
The force by the pulley on the lower block will be F towards the right, and F downwards.
Meaning that in the direction parallel to the floor, only the reaction of the friction force between M1 and M2 will act on M2,to the right, right?
 
AlchemistK said:
The force by the pulley on the lower block will be F towards the right, and F [STRIKE]downwards[/STRIKE]. upward
Meaning that in the direction parallel to the floor, only the reaction of the friction force between M1 and M2 will act on M2,to the right, right?

So the net force that the rope exerts on block #2, via the pulleys, is zero.
 
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