
#1
Nov1012, 12:11 AM

P: 38

So I derived this equation for the net force/acceleration of a motorcycle on a flat surface. I beleive this equation could practically be used for any rolling object.
ƩF = F_{p}  μ*F_{n}  F_{D} Where: F_{P} is the force of the bike acting against the ground, tangent to the ground F_{D} = [itex]\frac{1}{2}[/itex]pv^{2}C_{D}A (air drag) μ*F_{n} is the frictional force of the tires, F_{n} is the normal force. Now to find a: ma = F_{p}  μF_{n}  F_{D} a = (F_{p}  μF_{n}  F_{D}) / m Is there anything wrong with this? 



#2
Nov1012, 01:37 AM

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#3
Nov1112, 09:53 PM

P: 38

Your kidding. Irregulaly shaped objects like apples?
Well you would need to run a model of a 3D apple through a simulator. There can't possibly be an equation to model that. My bad, that's why you can't use this for every rolling object. Only for surfaces that are nearly perfectly circular. 



#4
Nov1112, 10:01 PM

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Wrote general equation for a free body diagram
How about a regular shaped object then, like a polyhedron?
A hollow sphere with another, much smaller but heavy, solid sphere free to roll inside it? You did claim that the equation could be "used for any rolling object". You asked "in there anything wrong with this?" Now you know. 


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