1. The problem statement, all variables and given/known data Three blocks are released from rest and accelerated at 1.5 m/s^2. What is the magnitude of the force of friction on the block sliding horizontally? 2. Relevant equations F net = Mass * Acceleration (adding up 3 EQ's and canceling out variables) *Tension # = Tension sub # * Force of gravity = F sub g * Force of friction = F sub s 3. The attempt at a solution I made three equations: F sub g - T sub 1 = 4a <---- Block on farthest right T sub 1 - F sub s - T sub 2 = 4a <---- block on table T sub 3 - F sub g = 2a <--- farthest left block *after canceling out variables from combing the EQ's* 4a+4a+2a = F sub s - T sub 2 + T sub 3 I do not know how to find the force of friction because i cannot find the tensions. I used F sub 1 two times because i thought since the 4kg boxes are equal in mass and are accelerating at the same value, the tension must be equal. The answer is 4.6 N. I think I labeled some tension wrong I think. Thanks!