Circular Motion and Static Friction Problem.. "The Wall of Death" ride 1. The problem statement, all variables and given/known data A fairground ride called "The Wall of Death" consists of a cylindrical container of internal diameter 6.50m, mounted on a cylindrical axis. The passengers feel as if they are being pushed against the wall as the container begins to rotate. Eventually, the floor is lowered, leaving the miserable passengers pinned to the wall, apparently defying gravity. When the ride slows down, the passengers just begin to slide down the wall when they are rotating at 0.400 revolutions per second. Calculate the coefficient of static friction between the wall and the passengers' backs. 2. Relevant equations max static friction=coefficient*normal force? v= 2pi*r/T 3. The attempt at a solution I calculated how long it takes to go around in one second (period T) .4x=1 So, 1 rev=2.5 seconds. Now that I have T I also calculated the tangential velocity using the equation above and got 8.17m/s. I think the friction force would be set up as v-f=0 (used free body diagram...tangential velocity and friction cancel out to equal zero?) Which would mean force of friction is 8.17 too. I'm not sure if this is correct, but anyways, i don't know how to find the coefficient of static friction. I would think you would need to know the mass of the person.