- #1
whitejac
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Homework Statement
9.12)
The mass of the box on the left is 30kg and the mass of the box on the right is 40kg. The coefficient of static friction between each box and the inclined plane is μs = 0.2. Determine the minimum angle α for which the boxes will remain stationary.
Homework Equations
μsN = Fs
Equillibrium Equations
The Attempt at a Solution
As you can hopefully see, Box 1 is the yellow box on the right and box 2 is the blue box on the left. My problem is finding N in the second equation. It's just looking too nasty...
Box 1:
Fx = T - Fs - Mgcos(30)
Fy = N - MgSin(30)
Mg = 392.4 => N = 196.2 => Fs39.24 => T = 379.04
Box 2:
Fx = T - Fs - Mgcos(α)
Fy = N - MgSin(α)
Mg = 294.3 => α = Cos-1(N / 294.3)
This answer isn't very useful to me... You can see at the bottom of my notes I tried making substituting alpha into Fx, but it gives a nasty thing to factor. Historically this means I screwed up somewhere rather than the problem being this complicated...?