If a small motor does 520 J of work to move a toy car 260 m, what force does the engine exert on the car?

Two large, flat, horizontally oriented plates are parallel to each other, a distance d apart. half way betwween the two plates the electric field has magnitude e. if the separation of the plates is reduced to d/2 what is the magnitude of the electric field half way between the plates?

If an electric circuit is not grounded it is best to reach out and touch it to provide the ground a. true or b. false

Which of these has some mechanical energy? a. an atom b. heat inside earth c. a book on a shelf d. the fire from a lit match