The diagram shows the electric field around a point charge. The electric field points radially outward from the point. The magnitude of the electric field
A)
Decreases linearly as you move out from the charge.
B)
Increases linearly as you move out from the charge.
C)
Decreases proportional to the square on the distance from the charge.
D)
Increases proportional to the square on the distance from the charge.

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