Tension of string holding one mass to a wall, on top of another moving mass?

AI Thread Summary
A physics student is seeking help with a problem involving two blocks, where a horizontal force is applied to the lower block while the upper block is tethered to a wall. The scenario includes a 4.82 kg block on top of a 10.7 kg block, with a coefficient of kinetic friction of 0.197 between the surfaces. The student is unsure how to calculate the normal forces needed to determine the frictional forces and how these relate to the tension in the string. The key to solving the problem lies in recognizing that the frictional forces act in opposite directions for the two blocks. Understanding these dynamics will allow for the calculation of the tension in the string.
finniusmorgan
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Hello!
This is my first post, I am taking an introductory physics course during my second semester of college and having some trouble with this problem. I hope I have followed the correct format, I appreciate any help that can be offered!

Homework Statement



A 4.82 kg block is placed on top of a 10.7 kg
block. A horizontal force of F = 69.7 N is
applied to the 10.7 kg block, and the 4.82 kg
block is tied to the wall. The coefficient of
kinetic friction between all moving surfaces
is 0.197. There is friction both between the
masses and between the 10.7 kg block and the
ground.
The acceleration of gravity is 9.8 m/s2 .

Homework Equations



F=ma
f= [coefficient of friction]*Fn


The Attempt at a Solution



I really don't know how to find the normal forces that are used in finding the frictional force, but after that I would subtract the friction from the horizontal force to find the net force on the bottom (10.7kg) object, but I do not understand how to relate that to the tension in the string holding the second object.

Thank you!
 
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Hint : The frictional force between the blocks acts in different directions for the bodies. Tension can be calculated from it..
 

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