1) If the earth's electric field is 100 N/C downward, what must be the charge on a 1-kg object so that it would be "weightless"?

2) A spherical, non-conducting shell of inner radius r1= 10cm and outer radius r2 = 15 cm carries a total charge Q = 15 ?C distributed uniformly throughout its volume. What is the electric field at a distance r = 12 cm from the center of the shell?

#3)

Three point charges of -2.00 JC, +4.00 uC, and +6.00 JC are placed * P along the x axis as shown in the figure. What is the electrical potential 0.200 m at point P due to these charges? -2.00 & C +6.00 & C 0.200 m 0.200 m +4.00 u C