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# Help needed in M1 pulley watch

1. Hi guys

Can anyone help me with Q12 part C?
How to I calculate the magnitude of the tension exerted by the string? Do I look at the components of the weight of each particle, or the tension between them?

I am so confusing with the direction of the force as well.
Thanks

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2. (Original post by 123321123)

Hi guys

Can anyone help me with Q12 part C?
How to I calculate the magnitude of the tension exerted by the string? Do I look at the components of the weight of each particle, or the tension between them?

I am so confusing with the direction of the force as well.
Thanks

Posted from TSR Mobile
For part c, you're only interested in the pulley. The forces acting on the pulley are the two tensions, and the reaction to them.

You just want the two tensions which act along the lines of the string, at 30 degrees to the horizontal.

Tension acts away from the pulley.
3. on your diagram you need to put two tensions by the pulley ; they must point away from it.
4. (Original post by 123321123)

Hi guys

Can anyone help me with Q12 part C?
How to I calculate the magnitude of the tension exerted by the string? Do I look at the components of the weight of each particle, or the tension between them?

I am so confusing with the direction of the force as well.
Thanks

Posted from TSR Mobile
Your work doesnt show properly but what I know is that the direction of force where the acceleration acts is subtracted to other forces opposing it to get a resultant force
5. Try to draw vectors in the forces acting on the two bodies .. I think that will help
6. (Original post by the bear)
on your diagram you need to put two tensions by the pulley ; they must point away from it.
Thanks, that 's really helpful. I get it.

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7. (Original post by ghostwalker)
For part c, you're only interested in the pulley. The forces acting on the pulley are the two tensions, and the reaction to them.

You just want the two tensions which act along the lines of the string, at 30 degrees to the horizontal.

Tension acts away from the pulley.
Thanks for your explanation, it helps me a lot.

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Your work doesnt show properly but what I know is that the direction of force where the acceleration acts is subtracted to other forces opposing it to get a resultant force
Thanks , I understand now.

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9. (Original post by 123321123)
Thanks , I understand now.

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ohkay can u explain it to me?caz' I think I have not gotten it right
10. The question c) asks you calculate the resultant force exerted by the string on the pulley. Therefore you only look at the force acted on the pulley which are the two tensions. You can just calculate the resultant force of two tensions.

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ohkay can u explain it to me?caz' I think I have not gotten it right
Forget to quote, sorry

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