Julie drives 100 mi to grandmother's house. on the way to grandmother's, julie drives half the distance at 30.0 mph and half the distance at 70.0 mph . on her return trip, she drives half the time at 30.0 mph and half the time at 70.0 mph . what is julie's average speed on the way to grandmother's house?
what is her average speed on the return trip?

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