Pulley, Mechanics question

by AlchemistK
Tags: mechanics, newton's laws, pulley
AlchemistK is offline
Jul7-11, 06:15 AM
P: 158
1. The problem statement, all variables and given/known data

Find the reading of the spring balance shown in the figure (see attachment). The elevator is going up with an acceleration of g/10 , the pulley and the string are light weight and the pulley is smooth.

2. Relevant equations
F= ma

3. The attempt at a solution
Since the elevator is accelerating upwards with a magnitude of 0.98 m/s^2 (g/10) , the acceleration acting on the items in the elevator should be g+g/10 = 10.78 m/s^2.
By assuming that the 3k load has a relative acceleration of "a", the tension on the string of the 1.5 kg load will be
16.7 - 3a
While on the 3kg load it will be
32.34 + 3a

I'm sure i have made a blunder somewhere up here, yet i cant seem to find it. How do i further solve the question?
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Apophilius is offline
Jul7-11, 08:51 AM
P: 14
Maybe it's just me, but I can't locate the attached image

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