I Static friction vs. Normal force on an incline

Alex75 · Jun 30, 2016

I have two surfaces that have a coifficent of friction of .6. Disregarding mass (if possible) at what angle would the force of static friction and the normal force be equal

gleem · Jun 30, 2016

Alex75 said: ↑

Disregarding mass (if possible) at what angle would the force of static friction and the normal force be equal

Not possible. The normal force depends on the mass. Since the frictional force is equal to the coefficient of friction times the normal force they can never be equal unless the coefficient of friction is one and that would be true of any angle.

Alex75 · Jun 30, 2016

This problem relates to woods chips sliding down a steel slide they range in mass from one gram to 500 grams what would the minimum angle be so that the normal force applied to every chip would overcome the force of static friction on each individual chip

gleem · Jun 30, 2016

I see the situation. The problem is asking at what angle will the chips begin to slide over one another. and that will occur when the force that is causing them to slide is equal to the frictional force that is preventing them from sliding. The normal force is not the force which will overcome the friction. The normal force is that which determines the frictional force. What force is acting such as to cause the chips down the slide?

Alex75 · Jun 30, 2016

The acceration of gravity acting soon an incline

Alex75 · Jun 30, 2016

*upon

gleem · Jun 30, 2016

And what would that be in the case of a slide at an angle Θ?

Alex75 · Jun 30, 2016

Mgsin°=n

Alex75 · Jun 30, 2016

Where m is mass
G is acceleration of gravity
° is the angle of the steel slide
N is normal force applied to object

gleem · Jun 30, 2016

according to that if the slide is at 0 deg then the normal force is 0? Is that OK with you?

Alex75 · Jun 30, 2016

No I am trying to determine the minimum angle the slide needs to be placed at so the chips accelerate down the slide. I.e. when the force from gravity is enough to overcome the static friction of the chips

gleem · Jun 30, 2016

I was questioning your formula for the normal force.

gleem · Jun 30, 2016

MgsinΘ is not the normal force so what is the normal force?

Alex75 · Jun 30, 2016

That was the equation I found when reshuching frictional forces

gleem · Jun 30, 2016

May I ask your physics background?

Alex75 · Jun 30, 2016

Ff=un
Ff is frictional force
U is the coifficent of friction
N is normal force

Alex75 · Jun 30, 2016

None really outside college physics when I was a senior I have always had a love for science and physics though which is way I am attempting to educate myself on what I still need to learn and refresh what I already know

gleem · Jun 30, 2016

Do you remember the idea of the resolving (splitting) of a force ( i.e., a vector) into components? That is such that if you add the components you get the original force (vector) back>

Alex75 · Jun 30, 2016

Vaguely

Alex75 · Jun 30, 2016

I believe that was what we ended up doing in physics class to determine at what angle a car's tires would loose friction between the road surface