Exam 20: Electric Fields and Forces

Two tiny beads, each of mass 3.2 g, carry equal-magnitude charges. When they are placed 6.4 cm apart and released in outer space, they begin to accelerate toward each other at 538 m/s². What is the magnitude of the charge on each bead? (k = 1/4πε₀ = 9.0 × 10⁹ N ∙ m²/C²)

As shown in the figure, the charge Q is midway between two other charges. If $Q = - 7.5 \mathrm { nC } ,$ what must be the charge q1 so that charge q2 remains stationary as Q and q1 are held in place?

Two electrons are $20.0 \mathrm {~mm}$ apart at closest approach. What is the magnitude of the maximum electric force that they exert on each other? (e = 1.60 × 10^-19 C, k = 1/4??₀ = 9.0 10⁹ N ? m²/C²)

Three equal charges +Q are at three of the corners of a square of side d. A fourth charge +Q of equal magnitude is at the center of the square as shown in the figure Which one of the arrows shown represents the net force acting on the charge at the center of the square?

A +5.00-μC point charge is placed at the 0.0 cm mark of a meter stick and a -4.00-μC point charge is placed at the 50.0 cm mark. At what point on a line through the ends of the meter stick is the electric field equal to zero?

How far apart should two protons be if the electrical force of repulsion on each one is equal to its weight on the earth? (k = 1/4??₀ = 9.0 × 10⁹ N ? m²/C², e = 1.6 × 10^-19 C, m_proton = 1.67 × 10^-27 kg)