Question

A small glass bead has been charged to + 20 nC . A tiny ball bearing 2.0 cm above the bead feels a 1.4×10⁻² N downward electric force. What is the charge on the ball bearing?

Answer 1

Fak 121221 where K= 8.99 x 100 Nm2/C2 Case: - (6) 2,8929 are same sign. E r - F Oi, 9,8% are opposite sign. q - 8

7 oren? | F=1.4x102N For downward Force L2 = -Ve. 20cm F- R\นน Y=2cm = 0.02mo .. 1.4 X162 = 8.99x18x20x1091921 (0.02)2 91 = +20nc - 20X10-9c 1921 = 1.4x102 x (0.02)2 8.99x109x 20X10-9 = 0.000003114 x10-2 = 3.114X164 x 10-2 = 3.114x10-8 = 31.14x100c = 31.14 nc 2 h = -31.14 ne] Am = -31.14 nic Ant