They're two boxes connected on a pulley, each weighing 2 kg. Box 1 is on a 30 degree incline and box 2 is on a 60 degree incline.
a. Find the acceleration ignoring friction
b. Find the acceleration if the coefficient of kinetic friction is 0.1.
The Attempt at a Solution
I drew the free-body diagram. We are missing the pulling of pushing force (Fp), the tension force and the acceleration (which we are trying to find).
So this what I did for part a (ignoring friction):
- Ft=Fp + mgsinΘ - m1a1
I solved for tension force since we don't have that.
I substituted the equation from Box 1 for Ft so I could eliminate it.
- Fp+Fp+mgsinΘ-mgsinΘ - m1a1=m2a2
So I am left with Fp still, which we don't know. I am confused.
For part b, with coefficient of kinetic friction of .1, I did the same thing but I added Ffr for box #2 because I made it so that the pulling force and the tension force were in the same direction while the frictional force would obviously be opposing that. For box #1 I thought that Ft would be like the frictional force since it's opposing force (I made the box going down in #1) so I didn't even add it for that part.
Can you tell me what I am doing wrong.