Physics. Gr.11. Kinetic Friction.

AI Thread Summary
To calculate the coefficient of kinetic friction for a 9.0 kg wagon accelerated by a 25N force at 1.5 m/s², one must understand that the coefficient is represented as Mk in the friction formula Ff = Mk * FN. The normal force (FN) can be determined based on the weight of the wagon, which is affected by gravity. The problem involves applying Newton's second law (F = ma) while accounting for the opposing force of friction. The coefficient of kinetic friction is typically denoted by the Greek letter μ, distinguishing it from static friction, which has a higher value. Understanding these concepts is essential for solving the problem effectively.
Kazia
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Homework Statement


A force of 25N accelerates a 9.0 kg wagon at 1.5 m/s2. Calculate the coefficient of the kinetic friction.


Homework Equations


Ff=MkFN
^^Or at least I think so.


The Attempt at a Solution


What does the coefficient of the kinetic friction mean first off?
I honestly have no clue how to go about this question.
 
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Welcome to PF, Kazia!

The coefficient of friction is the Mk in Ff=Mk*FN, the formula for finding the force of friction if you know the "normal force" pushing an object against another surface. Quite often the greek letter μ is used instead of Mk. There are two values for the coefficient, a smaller one for kinetic (moving) friction and a larger one for "static" friction (when the object is not moving).

Your problem is basically and F = ma problem, but also has the force of friction subtracting away some of the applied F.
 

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