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Given the diagram, what is the tension in each string?

  • Thread starter laladude
  • Start date
  • #1
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Homework Statement




Given this diagram and the masses involved, what is the Tension in each string. All masses are 1kg.

Diagram provided

4.jpg


Sorry, the angle for T2 is 10°


Homework Equations





The Attempt at a Solution



I really don't know where to start.
 
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Answers and Replies

  • #2
Redbelly98
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For each mass, draw a force diagram.

Then use ∑Fx=max and ∑Fy=may. (And you should know what ax and ay are :wink:)
 
  • #3
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For each mass, draw a force diagram.

Then use ∑Fx=max and ∑Fy=may. (And you should know what ax and ay are :wink:)
okay, so for T1 and T2..

x-dir would be ∑Fx = - T1 cos30 + T2 cos10 = 0

y-dir would be ∑Fy = T1 cos30 + T2 cos10 + -mg = 0

Then solve for T1 = T2 cos10/cos30 = 0

Plug into y-dir eq. (T2 cos10/cos30) cos30 + T2 cos10 = mg

T2 = mg/1.97 which is 4.97.

Then plug T2 to T1. Correct?

Now I am uncertain about T3 and T4..
 
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  • #4
Redbelly98
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okay, so for T1 and T2..

x-dir would be ∑Fx = - T1 cos30 + T2 cos10 = 0
Yes, good.
y-dir would be ∑Fy = T1 cos30 + T2 cos10 + -mg = 0
Almost -- for the y-dir, we use sin instead of cos.
Then solve for T1 = T2 cos10/cos30 = 0
Except for the "=0" part, that is correct.
Plug into y-dir eq. (T2 cos10/cos30) cos30 + T2 cos10 = mg
Yes, except that there should be some sin's in there because of what I said before about the y-direction forces.
T2 = mg/1.97 which is 4.97.

Then plug T2 to T1. Correct?
Yes, that is the idea.
Now I am uncertain about T3 and T4..
Have a look at the forces acting on Mass #3.
 

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