Figure P8.36 shows a block of mass m resting on a 20° slope. The block has coefficients of friction µs = 0.83 and µk = 0.47 with the surface. It is connected via a massless string over a massless, frictionless pulley to a hanging block of mass m2 = 2.0 kg.
(a) What is the minimum mass m that will stick and not slip?
(b) If this mimimum mass is nudged ever so slightly, it will start being pulled up the incline. What acceleration will it have?
m_1 = 1.783kg
m_2 = 2.0kg
θ = 20 degrees
T = 19.6N
μ_k = 0.47
μ_s = 0.83
The Attempt at a Solution
I found the mass m_1 using.. (part A)
..and I tried to find the a_x using forces.. (Part B begins here)
T - f_k - m*g*sin(θ) = m*a_x
..which gave me the equation...
..and I am not sure if I am doing the math wrong but my answers are rejected.
Could anyone perhaps check my force diagram and algebra?
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