In Section 22.3 we claimed that a charged object exerts a net attractive force on an electric dipole. Lets investigate this. FIGURE CP22.77 shows a permanent electric dipole consisting of charges +q and -q separated by the fixed distance s. Charge +Q is distance r from the center of the dipole. Well assume, as is usually the case in practice, that s V r. a. Write an expression for the net force exerted on the dipole by charge +Q. b. Is this force toward +Q or away from +Q? Explain. c. Use the binomial approximation 11 + x2-n 1 - nx if x V 1 to show that your expression from part a can be written Fnet = 2KqQs/r3 . d. How can an electric force have an inverse-cube dependence? Doesnt Coulombs law say that the electric force depends on the inverse square of the distance? Explain

Chapter 23: Magnetic Flux and Faraday’s Law of Induction Flux=BAcos (thet) o Unit is Weber (Wb) o B is magnetic field o A is area Magnetic flux if used in the calculation of the induced emf Faraday’s Law: an emf is induced only when the magnetic flux though a loop changes with time Change∈ flux o Change∈time ) emf =−N ¿ Lenz’s law: an induced...