Why is it important to know the direction of the force applied to a moving object and the direction in which the object is moving when determining the work done on the object? a. only the component of the force perpendicular to the motion is used to calculate the work. b. if the force acts in the same direction as the motion, then no work is done. c. when there is an angle between the two directions, the cosine of the angle must be considered. d. a force at a right angle to the motion requires the use of the sine of the angle.

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.

Which best describes the first law of thermodynamics as compared to the second law of thermodynamics? a. the first law describes how thermal energy is conserved but not the direction it moves. b. the first law describes the direction thermal energy moves but not how it is conserved. c. the first law describes how thermal energy can be created but not how it can be destroyed. d. the first law describes how thermal energy can be destroyed but not how it can be created.

Convection currents are caused by differences in what two things?