Which of the examples is describing acceleration? * A roller coaster cart is stationary while passengers are loading.
A roller coaster cart slows down as it starts to climb the first hill.
A roller coaster cart is traveling at a constant speed along a straight section of the
track
None of these are examples of acceleration.

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