Two blocks with pulley, friction

AI Thread Summary
The discussion centers on a physics problem involving two blocks connected by a pulley, with specific masses and friction coefficients. The user seeks assistance in calculating the acceleration of the blocks, given the provided equations and parameters. They express frustration with the algebra involved and mention a recurring discrepancy in their calculations. The user requests help in visualizing the setup and guidance on the correct order of operations for solving the equations. Overall, the thread highlights the challenges of applying torque and force equations in a multi-body system.
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Homework Statement


Consider the setup shown below. The blocks
have masses 8.2 kg and 25 kg. The pulley
has mass 5.9 kg, and is a uniform disc with
radius 0.25 m. Assume the pulley to be fric-
tionless, but the coefficient of friction between
the block and the surface is 0.28.What is the
acceleration of the blocks? Assume the 25 kg
mass is descending with acceleration a. The
moment of inertia of the disk is 1/2MR2 and the
acceleration of gravity is 9.8 m/s2 .
Answer in units of m/s2.


Homework Equations


Torque= (radius)(force)sin(angle between them)= (inerta)*(alpha)or (inertia)*a/r
sumF=ma
friction= (mew)*(normal force)

The Attempt at a Solution


mo= mass of pulley

I think this problem just has too much algebra =.=
sumF1x= m1gsin(theta)+Friction-T1=m1a
SumF2y=T2-m2g=m2a
sumT= 1/2(mo)ra= rt1-rt2 ( I don't know which one should go first or why)
solving the t and plugging it into torque I receive:

a= g( (1+(mew))m1sin(theta)-m2)
-----------------------------
(1/2mo+m1+m2)

I have a practice problem I can use to verify if i set this problem up but I keep getting like .05 off -.-

Any help would be appreciated!
 
Last edited:
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Show a picture of the set-up and show your work.

ehild
 
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