Electrostatics Problems: Charges, Forces, and Fields
Iron atoms have been detected in the sun’s outer atmosphere, some with many of their electrons stripped away. What is the net electric charge (in coulombs) of an iron atom with 26 protons and 7 electrons? Be sure to include the algebraic sign (+ or -) in your answer.
Four identical metallic objects carry the following charges: +1.6, +6.2, -4.8, and -9.4 micro Coulombs. The objects are brought simultaneously into contact, so that each touches the others. Then they are separated. (a) What is the final charge on each object? (b) How many electrons (or protons) make up the final charge on each object?
Two spherical objects are separated by a distance that is 1.80 x 10-3 m. The objects are initially electrically neutral and are very small compared to the distance between them. Each object acquires the same negative charge due to the addition of electrons. As a result, each object experiences an electrostatic force that has a magnitude of 4.55 x 10-21 N. How many electrons did it take to produce the charge on one of the objects?
Two very small spheres are initially neutral and separated by a distance of 0.50 m. Suppose that 3.0 x 1013 electrons are removed from one sphere and placed on the other. (a) What is the magnitude of the electrostatic force that acts on each sphere? (b) Is the force attractive or repulsive? Why?
Two particles, with identical positive charges and a separation of 2.60 x 10-2 m, are released from rest. Immediately after the release, particle 1 has an acceleration a1 whose magnitude is 4.60 x 103 m/s2, while particle 2 has an acceleration a2 whose magnitude is 8.50 x 103 m/s2. Particle 1 has a mass of 6.00 x 10-6 kg. Find (a) the charge on each particle and (b) the mass of particle 2.
Suppose a single electron orbits about a nucleus containing two protons (+2e), as would be the case for a helium atom from which one of the two naturally occurring electrons is removed. The radius of the orbit is 2.65 x 10-11 m. Determine the magnitude of the electron’s centripetal acceleration.
An electric field of 260,000 N/C points due west at a certain spot. What are the magnitude and direction of the force that acts on a charge of -7.0 microC at this spot?
A uniform electric field exists everywhere in the x, y plane. This electric field has a magnitude of 4500 N/C and is directed in the positive x direction. A point charge -8.0 x 10-9 C is placed at the origin. Determine the magnitude of the net electric field at (a) x=-0.15 m, (b) x= +0.15 m, and (c) y= +0.15 m.
The magnitude of each of the charges in Figure 18.21 is 8.60 x 10-12 C. The lengths of the sides of the rectangles are 3.00 cm and 5.00 cm. Find the magnitude of the electric field at the center of the rectangle in Figures 18.21 a and b.
A particle of charge +12 microC and mass 3.8 x 10-5 kg is released from rest in a region where there is a constant electric field of +480 N/C. What is the displacement of the particle after a time of 1.6 x 10-2 s?
Two charges are placed on the x axis. One of the charges (q1 = +8.5 microC) is at x1 = +3.0 cm and the other (q2 = -21 microC) is at x1 = +9.0 cm. Find the net electric field (magnitude and direction) at (a) x = 0 cm and (b) x = 6.0 cm.
Two small objects, A and B, are fixed in place and separated by 3.00 cm in a vacuum. Object A has a charge of 2.00 microC, and object B has a charge of -2.00 microC. How many electrons must be removed from object A and put onto object B to make the electrostatic force that acts on each object an attractive force whose magnitude is 68.0 N?
A small object, which has a charge q = 7.5 microC and mass m = 9 x 10-5 kg, is placed in a constant electric field. Starting from rest, the object accelerates to a speed of 2.0 x 103 m/s in a time of 0.96 s. Determine the magnitude of the electric field.
