Homework Help: Tension in ropes connecting blocks

1. Mar 14, 2005

sevens

The figure shows two 1.0 kg blocks connected by a rope. A second rope hangs beneath the lower block. Both ropes have a mass of 250 g. The entire assembly is accelerated upward at
3.0 m/s^2
i found the force that pulls the system to be 32.0N
However the followup question states:
What is the tension at the top end of rope 1?

for a I have
$$\sum{}\ = F - T = ma$$

and for b I have

$$\sum{}\ = T - W = ma$$

since i knew my a was 3.0 m/s^2 i made the equations equal to each other, to find my tention.
$$(T - W)m = (F-T)m$$

I arived at the answer 25.1N which is wrong. i think it may have to do with the fact that the ropes have a mass I thought tension through out a rope was uniform no matter where on the string you are. :grumpy:

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2. Mar 17, 2005

xangel31x

ok you do it the same way you did the first part, except this time you only count the mass until the end of the first rope. i did this problem a couple of weeks ago. you are doing it on online homework aren't you?