# Homework Help: Pully systems help

1. Oct 9, 2012

### _MNice_

In the figure below, M2 has more mass than M1 and M1 has more mass than M3. The questions refer to the magnitudes of tensions and weights. There
is friction between the horizontal plane and M2 (mu_k not equal to 0). M2 is observed to travel at a constant speed. Assume that the pulleys are frictionless and have negligible mass. Select the appropriate symbol for each statement: T (True), F (False), G (Greater than), L (Less than), or E (Equal to). (If the first two are 'greater than,' and the last four 'less than,' then enter GGLLLL).
A) T1 is ... T2.
B) M1 g is ... T1.
C) The magnitude of the net force on M2 is T2 - T3.
D) M1 accelerates downwards.
E) T3 is ... T2.
F) T4 is ... M3 g.

F=ma

So far, I have: LExTLE, where x is unknown. Im not sure if these are right, just looking for some guidance on this problem really.
1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

#### Attached Files:

• ###### Pulley problem.gif
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2. Oct 10, 2012

### tiny-tim

Welcome to PF!

Hi _MNice_! Welcome to PF!
hmm … 2 out of 6 correct

almost everything in mechanics is done by applying F = ma

call the acceleration "a" (it's the same for all three masses), and apply F = ma to each of the three masses (separately)

(also to a tiny bit of string round each pulley)

show us what you get