Coefficient of static friction problem

In summary, the conversation discusses a problem involving a carnival ride called the "Rotor-ride" where people are rotated in a vertical cylindrical room. The question asks for the minimum coefficient of static friction needed to prevent people from slipping down when the floor drops out. The conversation includes calculations using the formula for circular motion and the concept of centripetal force. The final equation suggested is u = [(4pi^2)(f^2)(r)]/g, where u is the coefficient of static friction, f is the rotation frequency, r is the room radius, and g is the acceleration due to gravity.
  • #1
rykirk
2
0
Hey guys,

I was wondering if you could help me out with the following problem...

In a "Rotor-ride" at a carnival, people pay money to be rotated in a vertical cylindrically walled "room". If the room radius is 5.0 m and the rotation frequency is .60 revoloutions per second when the floor drops out, what is the minimum coefficient of static friction so that people will not slip down.

I keep getting stuck in the same place...I have calculated the velocity using the formula for circular motion that states v=(2*pi*r)/T, getting (10*pi)/2 and could easily get the acceleration of the ride by squaring the velocity and dividing by the radius..but I'm not 100% sure what to do after that. I know I need an equation in which the mass will cancel out on both sides, but I'm not sure how to tie the friction coefficient into the problem. :frown:

Any help would be greatly appreciated

Thanks alot,

Ryan
 
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  • #2
Remember in the cyclone the cetripetal force will be the normal force, (forces on x-axis) and on the y-axis we got the friction force pointin up and the weight pointing down.

Also a hint [tex] F_{f} = \mu N [/tex]
 
  • #3
perhaps the equation you are looking for is

u (coeffi of static friction)= [(4pi^2)(f^2)(r)]/g
 

FAQ: Coefficient of static friction problem

What is the coefficient of static friction?

The coefficient of static friction is a dimensionless value that represents the amount of force required to initiate motion between two surfaces in contact. It is dependent on the materials and surface conditions of the two surfaces in contact.

How is the coefficient of static friction calculated?

The coefficient of static friction is calculated by dividing the maximum force required to initiate motion between two surfaces by the normal force, or the force perpendicular to the surface. This ratio is a constant value for a given pair of surfaces.

What is the significance of the coefficient of static friction?

The coefficient of static friction is important in understanding the relationship between force and motion for objects in contact. It helps determine whether an object will remain stationary or start moving when a force is applied.

How does the coefficient of static friction affect an object's motion?

If the applied force is less than the maximum force of static friction, the object will remain stationary. However, if the applied force exceeds the maximum force of static friction, the object will start moving with an acceleration dependent on the coefficient of kinetic friction.

Can the coefficient of static friction change?

Yes, the coefficient of static friction can change depending on the materials and surface conditions of the two surfaces in contact. It can also vary with temperature, humidity, and other factors that affect the interaction between the surfaces.

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