Free body diagram Incline Problem

AI Thread Summary
The discussion centers on a physics problem involving two blocks, one resting on a table and the other hanging, with a focus on free body diagrams and frictional forces. Participants explore the static friction holding the blocks in place, noting that it must equal the force attempting to move them since they are stationary. The difference between static and kinetic friction is clarified, emphasizing that static friction applies when objects are not moving, while kinetic friction applies once they begin to slide. The problem also involves calculating the frictional force when the blocks start moving, given a coefficient of kinetic friction of 0.54. Understanding these concepts is crucial for solving the problem accurately.
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Problem: Block 1 is 7kg and is resting on a table with friction. Block 2.5kg is connected by a massless cord and is hanging over the side of the table. ( assume there is no friction on the cord where it goes over the side of the table.) The two masses are stationary but on the verge of sliding.
a.) Draw a free body diagram
b.) What is the magnitude of the frictional force holding the blocks in place? (static friction.)
c.) What is the coefficient of static friction between the table and the block?
d.) If you give the blocks a slight nudge, they begin to move. If the coefficient of kinetic friction is 0.54, what is the frictional force (kinetic) now that they are moving?

I draw the free body diagram and understand their is Fg, Fnormal, Ffriction, Ftension on block 1, then block 2 has Ftension and Fg. Not really sure what to do next to solve for frictional force. By the way what's the difference between static and kinetic friction? My book eludes this information to me.
 
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There is obviously a force from the block hanging over the table trying to pull the one on the table off. If they're on the brink of moving then the frictional force must be equal to the force trying to move them. Here is a link that has a couple of articles on the differences between the frictions.

http://hyperphysics.phy-astr.gsu.edu/hbasees/frict2.html
 
Kindly see the attached pdf. My attempt to solve it, is in it. I'm wondering if my solution is right. My idea is this: At any point of time, the ball may be assumed to be at an incline which is at an angle of θ(kindly see both the pics in the pdf file). The value of θ will continuously change and so will the value of friction. I'm not able to figure out, why my solution is wrong, if it is wrong .
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