# Homework Help: Pulley problem

1. May 18, 2017

### SqueeSpleen

1. The problem statement, all variables and given/known data
There's two blocks of mass m_{A} and m_{B} which are linked by an ideal string. The block of mass A descends at constant speed. There's no friction. If the pulley is ideal, which one of the following is true

2. Relevant equations
Newton laws and trigonometry I think.

3. The attempt at a solution
I think that the correct answer is the second one, but the first one is marked as correct so I wanted a second opinion.
My reasoning is the following: If the speed is constant it means there is no acceleration, so the sum of the forces is 0. Then I decomposed gravity in the component that's compensated by the normal force done by the triangle and it's perpendicular component. So I arrived to
m_{A} (1/2) = m_{B} sqrt(3)/2
Now that I check, it isn't item 2. it would fall in item 1 as 1/sqrt(3) is between 0.25 and 0.6
Right?

sorry for the typos, I broke my keyboard yesterday (I won't drink coffee while on computer again) and I'm with a rubber one until a new one arrives, at least it's better thanthe one that windows have to use with the mouse.

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2. May 18, 2017

### TomHart

Working it out very quickly, and thus prone to error, I think the first answer is correct.

3. May 18, 2017

### haruspex

Yes.

4. May 19, 2017

### AlphaLearner

Absolutely correct! Way of solving by simply taking their Sine components of 'g' and solve it.