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myulieth
Nov 9, 2011, 07:14 PM
Block A has a mass of 6.07 kg and is on a rough incline of 12.5o to the horizontal. Block B has a mass of 4.82 kg and the coefficient of kinetic friction between Block A and the plane is 0.268. What is the acceleration of the blocks? What is the tension in the string?

Could someone please explain this to me? Thanks
http://i1127.photobucket.com/albums/l631/myulieth07/2blockinc.gif (here is the picture in case you want to see it)

Unknown008
Nov 9, 2011, 10:37 PM
You have to make two equations here, one for each block. First make an assumption. I will assume block A pulls up block B since A is heavier, but we'll see what it will turn out to.

For block A:
F_A = F_g - T - F_f

From the previous assumption, the force of gravity down the plane should be larger than the tension and the force of friction acting up the plane.

For block B:
F_B = T - F_g

The tension in the rope is greater than the weight of the box, so that the box moves up.

Now, you can find Ff, find each of the Fg and use F = ma for each box on the left side:

F_A = F_g - T - F_f

m_Aa = F_g - T - F_f... (1)

F_B = T - F_g

m_Ba = T - F_g... (2)

Can you simplify those two equation with the data you were given? We'll continue when you are done with that.