2. Fill in the blanks a. Two bodies are rubbed against each other they acquire and
charges.
b. are transferred from one object to another when two objects are charged by
friction.
c. is a device used to secure tall buildings from the effect of lightning
d. charge is obtained by plastic comb when rubbed with dry hair.
e. Lightning is on huge scale

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