A 2.9 kg block moving along the x axis is acted upon by a single horizontal force that varies with the block’s position according to the equation Fx = a x2 + b , where a = 6 N/m2 , and b = −3.6 N. At 1.2 m, the block is moving to the right with a speed of 4.6 m/s. Determine the speed of the block at 2.7 m. Answer in units of m/s.

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