7. an elevator descends at a constant velocity. which of the following is true? a. the total energy of the elevator is conserved because energy is always conserved. b. the total energy of the elevator is not conserved because a non-conservative force does work on the elevator. c. the total energy of the elevator is conserved because no net external force acts on the elevator. d. the total energy of the elevator is not conserved because a net external force acts on the elevator.

Which statement correctly describes a step-up transformer? a. it increases the amount of electric energy available. b. it increases the voltage of an electric current. c. it changes direct current into alternating current. d. it has more loops of wire in its primary coil.

What is friction? how does it affect the motion of an object?

Place several e-field sensors at a few points on different equipotential lines, and look at the relationship between the electric field and the equipotential lines. which statement is true? 1-at any point, the electric field is perpendicular to the equipotential line at that point, and it is directed toward lines of higher voltages. 2-at any point, the electric field is perpendicular to the equipotential line at that point, and it is directed toward lines of lower voltages. 3-at any point, the electric field is parallel to the equipotential line at that point.