Tension with connected blocks

1. Sep 23, 2009

tigerlili

1. The problem statement, all variables and given/known data
three connected blocks are pulled to the right on a horizontal frictionless table by a force of magnitude T3 = 13.8 N. If m1 = 15.1 kg, m2 = 24.8 kg, and m3 = 30.5 kg, calculate (a) the magnitude of the system's acceleration, (b) the tension T1, and (c) the tension T2.

(the figure has 3 blocks in this order: 1----2-----3--- being pulled by a hand on this side

2. Relevant equations

f=ma

3. The attempt at a solution

well, i got part a. that was just the sum of the masses, using t3 as the force in the f=ma equation. now, for the next part, i would think that the tension on block 2 would be the sum of block 1 and 2 (because they go in decreasing order) times the acceleration. likewise, i would think that block 1's tension would just be... the mass of block one times the acceleration. evidently that is wrong, so i'm just wondering if someone can give me a hand. thanks!

EDIT:
..this was actually correct
just, the way i was entering it was wrong
ignore this post, sorry! :)

Last edited: Sep 23, 2009