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## Homework Statement

http://imgur.com/vgLv6NY

The figure shows a system of masses and pulleys. Assume the masses slide without friction and the pulleys have negligible mass.

**Calculate the tension in the string.**

Data: M1 = 2.1 kg; M2 = 1.4 kg; M3 = 1.6 kg;

## Homework Equations

f=ma

## The Attempt at a Solution

I don't know what it is about this pulley system that is throwing a wrench in the cogs but I just can't find the correct answer.

I know that the acceleration of M

_{1}will be lower than that of M

_{2}. I also believe that the acceleration of M

_{3}must equal that of M

_{1}+ M

_{2}.

a

_{1}=(M

_{3}g-M

_{2}a

_{2}) / (M

_{1}+M

_{2}+M

_{3})

Similar for a

_{2}.

a

_{3}=M

_{3}g / (M

_{1}+M

_{2}+M

_{3})

Are my assumptions correct? I tried to use these equations to solve for a

_{2}. Since a

_{2}is the limiting factor on the tension due to it being the lightest of the two resisting forces the total tension should just be equal to M

_{2}*a

_{2}.

What I got:

a

_{2}=0.76541 m/s

Tension=m

_{2}*a

_{2}=1.072 N

Does that sound right?

Thank you!

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