Centripetal Force: Calculate Tension for 35kg Boy

AI Thread Summary
To calculate the tension in the rope for a 35kg boy swinging at the lowest point with a speed of 3 m/s, the relevant equations include F=ma and F=(m*v^2)/R. Initially, the calculated force was 45N, but this did not account for the boy's weight. The correct calculation includes adding the gravitational force (weight) of the boy, which is 35kg multiplied by 9.8m/s², resulting in a total tension of 388N in the rope. This highlights the importance of considering both centripetal force and gravitational force in such problems. Accurate calculations are essential for determining the correct tension in the rope.
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Homework Statement



A 35kg boy is swinging on a rope 7 m long. He passes through the lowest position with a speed of 3 m/sec. What is the tension in the rope at that moment?

Homework Equations



F=ma
F=(m*v^2)/R
v=(2pi*r)/T

The Attempt at a Solution



F=(35*3^2)/7=45N

The correct answer is supposed to be 388 though.
 
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Remember there is also the weight of the boy
 
Oh...yeah...thanks! That does it. 45+35*9.8=388.
 

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