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# Mechanics 1 FORCE ON PULLEY watch

1. I can't figure out how to work out the angle of the force on the pulley of this question. I tried adding up the vectors but I must be doing something wrong.

Particles A and B of masses 0.2 and 0.1 respectively are joined by a light inextensible string with A on a smooth plane inclined at 10 degrees to the horizontal and B hanging vertically off a pulley at the bottom of the plane.
Find the value of the angle the resultant force exerted on the pulley by the string acts below the horizontal.

I've worked out the tension in the string on both sides is 0.5298831....N but I can't work out the resultant angle of the force on the pulley
2. (Original post by Bobrey)
I can't figure out how to work out the angle of the force on the pulley of this question. I tried adding up the vectors but I must be doing something wrong.

Particles A and B of masses 0.2 and 0.1 respectively are joined by a light inextensible string with A on a smooth plane inclined at 10 degrees to the horizontal and B hanging vertically off a pulley at the bottom of the plane.
Find the value of the angle the resultant force exerted on the pulley by the string acts below the horizontal.

I've worked out the tension in the string on both sides is 0.5298831....N but I can't work out the resultant angle of the force on the pulley
Check your value for T before you attempt the second part.

Anyway, I was taught that the general formula of finding the resultant force on a pulley is 2Tcos(half of the angle)
So once you have found the value of T, then find the angle at the very top of the triangle where the pulley is and half it.

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Updated: June 16, 2016
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