1.

The membrane surrounding a living cell consists of an inner and an outer wall that are separated by a small space. Assume that the membrane acts like a parallel plate capacitor in which the effective charge density on the inner and outer walls has a magnitude of 7.0 * 10" C/m. (a) What is the magnitude of the electric field within the cell membrane? (b) Find the magnitude of the electric force that would be exerted on a potassium ion (K*; charge = +e) placed inside the membrane. (a) Number i Units (b) Number UnitsA 2.7 JC point charge is placed in an external uniform electric field that has a magnitude of 66000 N/C. At what distance from the charge is the net electric field zero? Number i Units vA tiny ball (mass = 0.015 kg) carries a charge of -17 /C. What is the electric field magnitude that would cause the ball to float above the ground? Number i UnitsReview Conceptual Example 11 before attempting to work this problem. Four charges with equal magnitudes of 7.03 x 10-12 Care placed at the corners of a rectangle. The lengths of the sides of the rectangles are 3.83 cm and 7.03 cm. Find the magnitude of the electric field at the center of the rectangle in Figures a and b. +4 (a) (a) Number i Units (b) Number i UnitsTwo charges are located on the x axis: q1 = +8.4 /C at x1 = +4.9 cm, and q2 = +8.4 //C at x2 = -4.9 cm. Two other charges are located on the y axis: q3 = +3.7 pCat y3 = +4.8 cm, and q4 = -9.8 /Caty4 =+7.1 cm. Find (a) the magnitude and (b) the direction of the net electric field at the origin. 43 42 41 (a) Number Units (b) The net electric field points