Q1. A charge of 28.0 {rm nC} is placed in a uniform electric field that is directed vertically upward and that has a magnitude of 4.00×104 N/C. What work is completed by the electric force when the charge moves?
Q2. An observer, whose eyes are 1.99 m above the ground, is standing 35.0 m away from a tree. The ground is level, and the tree is growing perpendicular to it. The observer's line of sight with the treetop makes an angle of 23.0° above the horizontal. How tall is the tree?