A student attaches a rope to a 6.7 kg box of books. He pulls with a force of 32 N at an angle of 30° with the horizontal. The coefficient of kinetic friction between the box and the sidewalk is 0.32. Find the acceleration of the box.

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