Two 1.2m nonconducting wires meet at a right angle. One segment carries 2.5µC of charge distributed uniformly along its length, and the other carries −2.5µC distributed
uniformly along it, as shown in Fig. P21.99. (a) Find the magnitude and direction of
the electric field these wires produce at point P, which is 60.0cm from each wire. (b) If
an electron is released at P, what are the magnitude and direction of the net force that
these wires exert on it?

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