Coefficient of Friction (Styrofoam on Water)

AI Thread Summary
The discussion centers on calculating the coefficient of friction for a styrofoam object on water. The participant outlines the gravitational force and net force equations but encounters confusion regarding the calculations, particularly noting a discrepancy in the net force value. They question whether friction is the only force acting on the styrofoam or if other forces are involved, which complicates the analysis. The conversation emphasizes the need to clarify the forces at play to accurately determine the coefficient of friction. The participant is seeking guidance on resolving these mathematical inconsistencies and understanding the forces involved.
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Homework Statement



fgrav = mg
fgrav = (0.0821)(9.8) = 0.80458 N

fnet = ma = (0.0821)(0.0096) = 0.0096 m/s^2

fnorm = fgrav

Homework Equations



kinetic mew = force of friction / fnorm

The Attempt at a Solution



Required: Ffr

kinetic mew = force of friction / fnorm
kinetic mew = force of friction / 0.80458 N

I need to find the friction of the object when it is on the water. The object is made out of styrofoam. I'm completely stumped and I tried looking around internet using the google search engine to find the coefficient of friction of two surfaces.
 
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dashed said:

Homework Statement




fnet = ma = (0.0821)(0.0096) = 0.0096 m/s^2

This does not make much sense...mathematically, it is not true. (0.0821)(0.0096) = 0.00079.

Also...what forces are acting on this styrofoam contributing to fnet? is friction the only force and the styrofoam is actually slowing down? Or are there other forces involved?

If it is the first case, then 0.00079 = force of friction and "mu" can be calculated as per the equation you show. If it is the second case, the force of friction can be calculated using the fnet equation and the values of the other forces involved.
 
Galileo's Ghost said:
This does not make much sense...mathematically, it is not true. (0.0821)(0.0096) = 0.00079.

Also...what forces are acting on this styrofoam contributing to fnet? is friction the only force and the styrofoam is actually slowing down? Or are there other forces involved?

If it is the first case, then 0.00079 = force of friction and "mu" can be calculated as per the equation you show. If it is the second case, the force of friction can be calculated using the fnet equation and the values of the other forces involved.

there is Fa which is opposite of Ffr. However at the moment Fa is unknown.
 
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