- #1

AJKing

- 104

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## Homework Statement

A pendulum bob of mass 2.5kg is pulled aside by a horizontal rope. If the tension in the rope is 3.50N, what is the angle between the pendulum and the vertical?

m

_{p}= 2.5 kg

T

_{r}= 3.50 N

F

_{g}= 2.5kg * 9.8m/s

^{2}

## Homework Equations

∑F = 0

Pocket full of trig functions and laws.

## The Attempt at a Solution

I've been over thinking this one like a moe'sucka.

Imagining the pendulum, one may speculate that there are 3 forces acting on the bob: the force of Gravity, Tension on the pendulum rope, and the force of Tension on the horizontal rope.

It's a pretty basic under those terms, and solving it reveals:

θ = 8.1°However, I don't feel like I've solved this correctly. [Edited explanation here, was going to rewrite it but then came to a conclusion.]

My biggest question is:

**Do I have to concern myself with the applied force of gravity (perpendicular to the neutral force) in this instance?**

If so, the question becomes much more stressing to solve. In this case, the tension in the horizontal rope becomes the horizontal factor of the perpendicular force.

I've expended most of my "goto" methods for solving these kinds of questions and even got a little crazy with trig stuff but I can't find that angle if I assume that 3.5N is only the x factor of the perpendicular force being balanced.

Any suggestions would be appreciated.

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