Tension In a String

  • Thread starter Lori
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  • #1
Lori

Homework Statement


upload_2017-11-4_22-13-46.png


Homework Equations



Ook, so i'm really bad at physics, and i need someone to help explain why the answer is P=T+25 N
I thought it is P+T = 125

The Attempt at a Solution



Since the system is in constant velocity, then Fnet = 0 so that P + T + W = 0 Why isn't it P + T + 125 =0?[/B]
 

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Answers and Replies

  • #2
jbriggs444
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Which direction does T pull on the 100 N weight?
Which direction does T pull on the 25 N weight?
 
  • #3
Lori
Which direction does T pull on the 100 N weight?
Which direction does T pull on the 25 N weight?
T always pull away from the object. So, for the 100 N weight, Tension pulls downward and for 25N, the tension pulls upward
 
  • #4
haruspex
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T always pull away from the object.
Yes.
So, for the 100 N weight, Tension pulls downward ...
Away from the 100N weight would be upwards, surely?
 
  • #5
CWatters
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Perhaps draw a two free body diagrams, one for each mass.
 
  • #6
Lori
Perhaps draw a two free body diagrams, one for each mass.
Thanks , i drew it for the 25 N object and got that P = T+25!

upload_2017-11-5_12-26-26.png
 

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Last edited by a moderator:
  • #7
Lori
I have a question to add!
If i know that W = T for the second diagram , then I know that T = 100N right?

I can actually find P since P = 25+T , so that P=125
 
  • #8
jbriggs444
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If i know that W = T for the second diagram , then I know that T = 100N right?

I can actually find P since P = 25+T , so that P=125
Right!
 

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