# Homework Help: Normal and Tangential Coordinates

1. Mar 16, 2013

### Northbysouth

1. The problem statement, all variables and given/known data
The 2-oz bead P is given an initial speed of 5 ft/sec at point A of the smooth guide which is curved in the horizontal plane. The horizontal force between the bead and the guide has a magnitude of 3 oz at point B.

Determine the radius of curvature ρ of the path at this point

I have attached an image of the question.
2. Relevant equations

3. The attempt at a solution

The question is fairly straightforward but I'm confused by the 'horizontal force'. My professor went over this example in class and when she drew the FBD she had the 3oz force pointing in the positive normal direction and I'm wondering if she meant for the question to say that the force is in the normal direction instead of in the horizontal direction.

Any insight would be appreciated.

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2. Mar 16, 2013

### TSny

Can you see that the "normal direction" is horizontal? So, finding the force in the normal direction will also give the force in the horizontal direction.