A rocket train car that is 30 m long is traveling from los angeles to new york at v=0.5c when a light at the center of the car flashes. when the light reaches the front of the car, it immediately rings a bell. light reaching the back of the car immediately sounds a siren. a bicyclist waiting to cross the tracks sees the light in front of her at the instant when it flashes. are the bell and siren simultaneous events for the bicyclist? if not, what time delay does the bicyclist hear between the events?

Athin nonconducting rod with a uniform distribution of positive charge q is bent into a circle of radius r. the central perpendicular axis through the ring is a z-axis, with the origin at the center of the ring. a) what is the magnitude of the electric field due to the rod at z = 0? n/c (b) what is the magnitude of the electric field due to the rod at z = infinity? n/c (c) in terms of r, at what positive value of z is that magnitude maximum? r (d) if r = 4.00 cm and q = 9.00 µc, what is the maximum magnitude? n/c