Why is the frictional force equation F = μN not equal to F = mg(cosθ)?

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The frictional force equation F = μN is distinct from F = mg(cosθ) because it accounts for the normal force, which varies based on the object's orientation and any additional forces acting on it. The normal force N is influenced by the object's mass, gravitational force, and the angle of inclination, making it essential for calculating friction accurately. While F = mg represents the gravitational force, it does not directly translate to friction without considering the normal force's adjustments. Friction acts parallel to the sliding surface and is proportional to the normal force, not solely dependent on gravitational force. Understanding these distinctions is crucial for accurately applying the frictional force equation in various scenarios.
the_new_guy
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Why isn't the force of friction F= (frictional constant)(force of gravity)?
Since F = mg(coefficiant)
and g is negative denoting the direction of the vector, gravitational force.
 
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What if your sliding object is pushed down by an extra force or if it is sliding on a inclined or curved surface?
 
The vector for friction is parallel to sliding surface and perpendicular to the normal force N. It is equal to the normal force multiplied by the coefficent of friction. The normal force N is a function of mass, g and the cosine of the inclination angle and whatever other forces that can be resolved in the normal direction.
 

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