In a plane electromagnetic wave, the E and B fields are:
Group of answer choices:
a. perpendicular and 90 degrees out of phase
b. parallel and 90 degrees out of phase
c. perpendicular and in phase
d. parallel and in phase
e. perpendicular, can be any phase relative to one another
f. parallel, can be any phase relative to one another

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