(adsbygoogle = window.adsbygoogle || []).push({}); 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!

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# Homework Help: Find force of friction

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