3. Three points charges are located at the corners of a rectangle. See figure. y (a) What is the magnitude of the electric 4, = 3.00 AC field at the empty corner? (12 points) 12.0 cm X 41 = 8.00 AC 5.00 cm 4, = 5.00 AC (b) If an alpha particle (q = +2e) is placed at the empty corner, what is the magnitude of the force on it? (3 points)