[Vadevalor]

A cable car is stationary,at eqm.3Forces act on it-Weight and 2 tension. They form a closed triangle,but why is the triangle isosceles?


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[jamesvancollier]

Cable cars are scary :s

[ben-smith]

(Original post by Vadevalor)
A cable car is stationary,at eqm.3Forces act on it-Weight and 2 tension. They form a closed triangle,but why is the triangle isosceles?


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The situation is symmetric thus the triangle also has a line of symmetry making it isosceles.

[Stevo F]

(Original post by Vadevalor)
A cable car is stationary,at eqm.3Forces act on it-Weight and 2 tension. They form a closed triangle,but why is the triangle isosceles?


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because it's at equilibrium, therefore it is halfway along the wire, therefore the tension forces must act in the opposite directions to one another and be of the same magnitude. As the weight force always acts only in the vertical plane, therefore the triangles on both sides must be the same size and shape, making an isosceles triangle when you put them together

[Stonebridge]

(Original post by Vadevalor)
A cable car is stationary,at eqm.3Forces act on it-Weight and 2 tension. They form a closed triangle,but why is the triangle isosceles?


This was posted from The Student Room's iPhone/iPad App

Only if it's half way along the wire. Then, as others have said, it's symmetry.

[Vadevalor]

I get the part about upward force by the tension forces must be equal to the downward force of weight,but why should the 2tension be of the same length(measured by magnitude of force)? One is 32 degrees left of the vertical ,one is 26 degrees above horizontal


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[Stonebridge]

(Original post by Vadevalor)
A cable car is stationary,at eqm.3Forces act on it-Weight and 2 tension. They form a closed triangle,but why is the triangle isosceles?


This was posted from The Student Room's iPhone/iPad App

Who says the triangles are isosceles? Please show the diagram.
They don't have to be isosceles.
If you have a specific physics question (preferably with the diagram you are referring to) it would help if we could see it.

My answer above (neg repped thanks, mate!) is correct.
The two tension forces are only equal if there is symmetry. That means the two ropes are at the same angle to the horizontal. That would be the case if the car was mid way along the ropes.
If the car is nearer one end, the angles are not equal and neither are the forces.

[Vadevalor]

This is the question, hmm..btw neg rep means i did smth bad? :0 im using iphone couldnt give you a good up sorry bout that but youre awesome


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[Stonebridge]

The diagram looks something like this if you draw a closed triangle.



The closed triangle means the forces are balanced.
You arrange the forces, keeping the orientations the same, so that they link end to end as shown.

I leave it to you to work out the angles in the vector triangle from inspection of the original diagram.

[Vadevalor]

Woot finally got it...so its cuz the angles r the same coincidentally,not general in fact -Dude, you are a genius.


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