1. The problem statement, all variables and given/known data In an old-fashioned amusement park ride, passengers stand inside a 5.4-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 0.64 to 1.0 and a kinetic coefficient in the range 0.40 to 0.70. A sign next to the entrance says "No children under 30 kg allowed." 2. Relevant equations f(fric)=(us)(n) Fr=n=mv^2/r Fz=f=mg Ft=0 w=v/r 3. The attempt at a solution f=(0.64)(9.8*30)=188.16N 188.16N=(30)(v)^2/2.7, v=4.1151m/s 4.115m/s/2.7=1.524rad 1.524rad/1s=1rev/2piradians=60sec/1min=143.65rpm This answer is not correct, however. Any guidance is appreciated. I don't want the answer, just what I am doing incorrectly.