1-Earth carries a net charge of -4.1 105 C. The force due to this charge is the same as if it were concentrated at Earth's center. How much charge would you have to place on a 9.0 g mass in order for the electrical and gravitational forces on it to balance?
2-An electron placed in an electric field experiences an electric force of 5.3 10-10 N. What is the field strength?
3-A 68 nC charge experiences a 140 mN force in a certain electric field.
A- Find the field strength that a 43 µC charge would experience in the same field
B- Find the force on the 43 µC charge.
4-What is the line charge density on a long wire if the electric field 44 cm from the wire has magnitude 220 kN/C and points toward the wire?
5-How strong an electric field is needed to accelerate electrons in a TV tube from rest to one-fifth the speed of light in a distance of 5.0 cm?