An infinitely long thin wire carrying linear charge densityλis brought close to a semi-infiniteneutral conductor which covers space forx < 0. the wire is a distancedaway and is orientedso that it is parallel to they−axis. calculate the force per unit length that acts on thewire.

Aball with a mass of 275 g is dropped from rest, hits the floor and rebounds upward. if the ball hits the floor with a speed of 2.40 m/s and rebounds with a speed of 1.70 m/s, determine the following. (a) magnitude of the change in the ball's momentum (let up be in the positive direction.)