- #1
Xiongster
- 8
- 0
Homework Statement
Hi, I have a problem here and I need some help on it. The problem is this:
block m_{1} weighs 875 N. The coefficient of static friction between the block and the table is 0.24 and the angle theta is 25.0\circ. Find the maximum weight of block m_{2} for which block m_{1} will remain at rest.
2. The attempt at a solution
So far I've drawn an FBD for m_{1}, m_{2}, and the knot that connects them.
For the block m_{1}, I have T_{1} = M_{s}N in the x-direction, and N = m_{1}g for the y-direction.
For block m_{2}, I have T_{2} = m_{2}g in the y-direction.
For the knot, I have T_{1} = T_{3}*cos(25) in the x-direction and T_{2} = T_{3}*sin(25) in the y-direction.
Since T_{1} = T_{3}*cos(25), and T_{1} = M_{s}N, I set T_{3}*cos(25) = M_{s}N and solving for T_{3}, I get T_{3} = (M_{s}N)/(cos(25))
In the knot, we have T_{2} = T_{3}*sin(25). I plug in the T_{3} derived earlier and T_{2} = m_{2}g into this equation to get m_{2}g = M_{s}*m_{1}g*tan(25)
When I plug in numbers, the answer I get is about 98, and that just doesn't seem right to me. Did I do something wrong? Thanks for the help in advance.
