D2.1. A charge Q₁ = -20 μC is located at 4(-6, 4, 7), and a charge QB = 50 μC is at B(5, 8, -2) in free space. If distances are given in meters, find: (a) RAB; (b) RAB. Determine the vector force exerted on QA by QB if €0 = (c) 10-9/(36л) F/m; (d) 8.854 x 10-12 F/m. Ans. 11ax +4ay - 9az m; 14.76 m; 30.76ax + 11.184ay - 25.16az mN; 30.72ax +11.169a, 25.13a mN -