Bottom of a pendulum, what is tension

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    Pendulum Tension
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Homework Help Overview

The problem involves a pendulum with a specified length and mass, focusing on calculating the tension in the string at the lowest point of the swing, given the speed of the bob.

Discussion Character

  • Mathematical reasoning, Problem interpretation

Approaches and Questions Raised

  • Participants discuss the application of centripetal force and the relationship between tension, gravitational force, and the motion of the pendulum. There are attempts to calculate the tension using different formulations and some questioning of the correctness of the results.

Discussion Status

Some participants have provided calculations for tension, while others question the validity of these results. There is an ongoing exploration of the relationships between forces acting on the pendulum bob, but no consensus has been reached regarding the correctness of the calculations.

Contextual Notes

Participants are working within the constraints of the problem's parameters, including the mass of the bob and its speed at the bottom of the swing. There is an implicit assumption that the calculations should align with the principles of dynamics and centripetal motion.

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A pendulum is 0.7 m long and the bob has a mass of 1.0 kg. At the bottom of its swing, the bob's speed is 1.6 m/s. What is the tension in the string at the bottom of the swing?

I know that I can use centripetal force, which can be calculated from v -

ma(c) = (mv^2)/r

I get 3.6571 N as my answer, why is this wrong? thanks
 
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The tension equals T = mv^2/r + mg.
 
T= 1(1.6^2)/.7 + 1(9.81) = 13.47 N

This is still incorrect... any other clues? thanks
 
what makes you think it's incorrect? ... cause it is correct.

at the bottom of the swing, Fnet = T - mg

mv^2/r = T - mg

T = mv^2/r + mg
 

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