Torque and Inertia of objects on Inclined plane

AI Thread Summary
The discussion revolves around determining the acceleration and tensions in a system involving two blocks connected by a string over a pulley on an inclined plane. The user successfully calculated the acceleration at 0.31 m/s² but is struggling to derive the tensions in the string, which are stated to be 7.67 N and 9.22 N. To find the tensions, applying Newton's second law to each block separately is recommended, but the user is not arriving at the expected values. There is also a request for clarification on the setup and a diagram to aid understanding. The conversation emphasizes the importance of accurately applying physics principles to solve for tensions in such systems.
cooltee13
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Homework Statement


a block with mass m1= 2 kg, and a block of mass m2 = 6kg are connected by a massless string over a pulley in the shape of a solid disk having radius R = .25m and mass M = 10 kg. These blocks are allowed to move on a fixed wedge of angle pheta = 30 degrees. the coefficent of kinetic friction is .36 for both blocks and pulley. Determine A) the acceleration of the two blocks and B) the tensions in the string on both sides of the pulley.


Homework Equations


well, I already solved part A) I just need help with part B. I used the sumTorque = Ialpha, where alpha = a/R. along with this equation below:


The Attempt at a Solution


well, i wanted to solve for a so i did the following:(note f=coefficent of friction*): -T1Rf+60cos(T2)Rf = 1/2mR^2*(a/R) ====> -T1f +60cos(T2)f = 1/2ma.

M2gf - T1f + 60cosT2f = 1/2Ma
M2gf = M1af + 60cosM2af + 1/2Ma
M2gf = a(M1f + 60cosM2f + 1/2M)
a = M2gf/(M1f + 60cosM2f + 1/2M) = .31 m/s^2

Im not sure how to solve for the Tension though, do i use the same equation??
 
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The answer for B is 7.67 N and 9.22 N.

But I want to know how they got that. Can anybody help please?
 
can anybody help? do I need to explain more?
 
A diagram would be helpful. Are both sides of the wedge at an angle of 30 degrees with the horizontal?

In any case, assuming you've correctly found the acceleration, just apply Newton's 2nd law to each block separately to find the tensions.
 
Im not sure how to put a diagram on this forum, but If i apply Newtons second law, I don't end up with the same Tensions as the book answer.

F = ma
I come up with 6.08 N for T1
 
Show exactly what you did to get the tension. (Until I understand the setup better, I cannot verify your answer for the acceleration.)
 
how do I insert an image so i can show you the picture?
 
One of the icons in the post editing window is for inserting images. Or you can attach a file.
 
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