Question regarding tension and friction

1. Sep 29, 2003

tristan_fc

Okay, well I've been working on this assignment forever now, and I have it all correct, but one last bit. Here's the problem.

Two blocks connected by a rope of negligible mass are being dragged by a horizontal force F. Suppose that F = 66.0 N, m1 = 10.0 kg, m2 = 20.0 kg, and the coefficient of kinetic friction between each block and the surface is 0.105.

The first part asked for the Tension of the rope between the blocks. I found that to be 22N. I have no idea how, because I had to find the acceleration to find the tension. I found the acceleration to be(incorrectly according to webassign) 2.095m/s^2.

So my question is how do I find the acceleration? I've done it every way I could see, and got 2.095 every time. Any ideas?

One more thing, this problem is due midnight central time.

Last edited: Sep 29, 2003
2. Sep 30, 2003

Sonty

First of all 66>(10+20)*10*0.105 so the system accelerates forward.
Both blocks will move with the same acceleration (obviously) so you just have to balance the forces on each block and write Newton's second. You'll get a system of two equations with two unknowns: a and T. Like this:
m1a=F-m1g&mu;-T