Ahoop (i = mr2) of mass 3 kg and radius 1.1 m is rolling at a center-of-mass speed of 11 m/s. an external force does 842 j of work on the hoop. what is the new speed of the center of mass of the hoop (in m/s)? round your answer to the nearest whole number.

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. part a what is the minimum rotational frequency, in rpm, for which the ride is safe? express your answer using two significant figures. f f = rpm