Two large, parallel metal plates each of area A are oriented horizontally and separated by a distance 3d. A grounded conducting wire joins them, and initially each plate carries no charge. Now a third identical plate carrying charge Q is inserted between the two plates, parallel to them and located a distance d from the upper plate as in the figure. 2d (a) What induced charge appears on each of the two original plates? (Use the following as necessary: Q.) On the lower plate the charge is On the upper plate the charge is (b) What potential difference appears between the middle plate and each of the other plates? (Use the following as necessary: 0, Q, A, and d.)