The discussion focuses on calculating friction forces for a 1326kg car on a flat surface, specifically addressing static and dynamic friction. To initiate movement, a force of 160N is required to overcome static friction, while a force of 120N is sufficient to maintain motion. The calculation of friction forces involves using the normal force and the coefficient of friction (μ). The user seeks clarification on whether to calculate friction forces or coefficients of friction, ultimately confirming the latter.
PREREQUISITESStudents preparing for physics exams, automotive engineers, and anyone interested in the principles of friction and motion in mechanics.
CWatters said:If I have understood correctly, the problem statement is telling you that to overcome the static friction you need to apply 160N. However once it's moving you only need to apply >120N to keep it moving. (eg this is a problem about static and dynamic friction).
However is the question really asking you to calculate the "friction forces" or the "coefficients of friction" ?
If the latter, look at the wikipedia entry for coefficient of friction. Hint: It's a ratio.
Sorry but I might not be able to return to this thread later.
azizlwl said:According Newton's 2nd law,
Fnet=ma
Fnet==F1+F2+F3+ ...Fn
Forces are vectors, so they have magnitude and direction.
If you take vector force pointing to the right is positive(vector as an arrow) , then vectors pointing to the left as negative.
As for the friction, the direction is always opposite of the motion of the object.
The value can be calculated by multiplying the Normal force to the kinetic coefficient μ.