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Homework Statement
Figure shows a block of mass m resting on a 20* slope. The block has coefficients of friction uS=0.80 and uK=0.50 with the surface. It is connected via a massless string over a massless, frictionless pulley to a hanging block of mass 2.0 kg.
Part A:
What is the minimum mass m that will stick and not slip?
Part B:
If this minimum mass is nudged ever so slightly, it will start being pulled up the incline. What acceleration will it have?
Homework Equations
Fnet=ma
us=F/N
The Attempt at a Solution
I really have no idea how to do Part B, but I tried part A and was real confident with my answer but it turned out wrong. This is what I did.
(2kg)(9.8)=19.6N for the hanging mass
assuming that the Hanging mass = to the tension force on the block with mass m I then did this...
19.6N=m(9.8)cos20*(.8)
m=2.66kg and this is wrong
Were did I go wrong?
Thanks
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