Suppose the coefficient of kinetic friction between ma and the plane in the figure(figure 1) is μk = 0.15, and that ma=mb=2.7kg.

a) as mb moves down, determine the magnitude of the acceleration of ma and mb, given θ = 35∘.

b) what smallest value of μk will keep the system from accelerating?

A ) 
T = mB g + mB a
T + mA a - mA g sin 35° = (Mi) mA g cos 35°

T = 2.7 · 9.81  + 2.7 a
T = 26.487 + 2.7 a
26.487 + 2.7 a + 2.7 a - 2.7 · 9.81 · 0.574 = 0.15 · 2.7 · 9.81 · 0.819
5.4 a + 26.487 - 15.2023 = 3.2539
5.4 a = 8.0296
a = 1.487 ≈ 1.5 m/s²
B )
T = 2,7 · 9.81 = 26.487 
26.487 - 15.2035 = (Mi) · 2.7 · 9.81 · 0.819
11.2835 = (Mi) · 21.69
(Mi) = 11.2835 : 21.69 = 0.52