(6%) problem 11: a small block of mass m = 850 g is placed on top of a larger block of mass 3m which is placed on a level frictionless surface and is attached to a horizontal spring of spring constant k = 4.1 n/m. the coefficient of static friction between the blocks is μ = 0.2. the lower block is pulled until the attached spring is stretched a distance d = 3.5 cm and released.

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