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Help with tension physics

A pulley is attached to the ceiling. Spring scale A is attached to the wall and a rope runs horizontally form it and over the pulley. The same rope is then attached to a spring scale B. On the other side of scale B hangs a 120 N weight. What are the readings of the two scales A and B? The weights of the scales are negligible.

please help
 

Answers and Replies

mezarashi
Homework Helper
650
0
I don't see why the scale readings shouldn't be the same. The pulley is considered mass-less correct?
 
145
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Well... If I have pictured it correctly then they would both read 120N

As there are in series so to speak. If they were in a parallel arrangement then it would be 60N each (that is if there were 2 strings holding from the ceiling).

I think the pulley is irrelevant and you could imagine the system just hanging from the ceiling.
 
Astronuc
Staff Emeritus
Science Advisor
18,542
1,684
Also, the question neglects friction in the pulley.

This is a statics problem and the question becomes, what can you say about the tension in the string? What is the effect of the pulley?
 
thanks thats what i thought also
 

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