How Fast Must the Cylinder Rotate to Keep Passengers from Sliding?

[jks8686]

Homework Statement

In an old-fashioned amusement park ride, passengers stand inside a 3.0-m-tall, 5.0-m-diameter hollow steel cylinder with their backs against the wall. The cylinder begins to rotate about a vertical axis. Then the floor on which the passengers are standing suddenly drops away! If all goes well, the passengers will “stick” to the wall and not slide. Clothing has a static coefficient of friction against steel in the range 0.60 to 1.0 and a kinetic coefficient in the range 0.40 to 0.70.

Homework Equations

T = 1/f

and so the people don't slide

(coefficient of friction) (Fn)= mg

( (coefficient of friction)*m*v^2)/ r = mg

The Attempt at a Solution

(coefficient of friction) = (g*r)/ (v^2)

T = (2*pi*r)/ square root of ((g*r)/(coefficient of friction))

and f= 1/T

I got 0.4068 = f
but the program says I am wrong

 

[berkeman]

What did you use for the coefficient of friction? What did you use for the radius?

 

[Doc Al]

Assuming that the question was to find the minimum frequency to insure that they wouldn't slide, it looks OK to me. How was the question phrased exactly?

 

[abs89]

The 0.4068 is rotations in a second. You had to multiply that value by 60 to put it into rotations per MINUTE.