\fF = 1 qq ATTEO r2 As = VigAt + as ( At ) 2 2 F = qE Ufs - Vis = asAt 1 9 2 - Vis = 2asAs ATTEr2 ar r Fnet = ma P = mi p = (qs, from negative to positive) 1 =PXE AP = FAt 1 2p 4187 73 (on axis) E ~ - 1 1 4near3 (bisecting plane) Constants & Other Useful Info 1 K = 1 - = 9x109 Nm2/C2 Common metric prefixes: e = 1.6x10-19 C giga- G 109 mega- M 106 Eo = 8.85 x 10-12 C2 / Nm kilo- mproton = mneutron = 1.67 x 10-27 kg k 103 centi- C 10-2 melectron = 9.11 x 10-31 kg milli- m 10-3 micro- 10-6 nano- n 10-9 pico- p 10-12 femto- -h 10-15(4) In the figure, a ring with radius 0.71 m has a charge of + 580 nC uniformly distributed over it. A point charge Q is placed at the center of the ring. The electric 4 potential is equal to zero at the point P, which is on + the axis of the ring, and 0.73 m from the center of the ring. + O (a) Is Q a positive or negative charge? Explain without doing any calculations. (b) What is the charge of