The bohr model of the hydrogen atom pictures the electron as a tiny particle moving in a circular orbit about a stationary proton. in the lowest-energy orbit the distance from the proton to the electron is 5.29 x 10-11 m, and the linear speed of the electron is 2.18 x 106 m/s. a) what is the angular velocity of the electron? b) how many orbits about the proton does the electron make each second? c) what is the electron❝s centripetal acceleration?

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