The figure below shows four particles, each with a positive charge, at the corners of a square. The length of each side of the square is a. The particle at top-right has a charge of q; the one at lower-left has a charge of 4.5q; the other two each have a charge of 5.5g. (Assume that the +x-axis is to the right and the +y-axis is up along the page.) a 5.59 a 4.5g 5.59 a (a) What is the magnitude of the force on the particle with charge q? Express your answer in terms of ke, q, and a in symbolic form. F = (b) What is the direction of the force on the particle with charge q? (Enter your answer in degrees counterclockwise from the +x-axis.) ° counterclockwise from the +x-axis

A 2.5-g copper penny is given a charge of 2.0109C . (a) How many excess electrons are on the penny? (b) By what percent do the excess electrons change the mass of the penny?

A particle with charge 3.00 nC is at the origin, and a particle with negative charge of magnitude Q is at x = 50.0 cm. A third particle with a positive charge is in equilibrium at x = 20.9 cm. What is Q?

Particle A of charge 3.00 104 C is at the origin, particle B of charge 6.00 101 C is at (4.00 m, 0), and particle C of charge 1.00 104 C is at (0, 3.00 in). We wish to find the net electric force on C. (a) What is the x component of the electric force exerted by A on C? (b) What is the y component of the force exerted by A on C? (c) Kind the magnitude of the force exerted by B on C. (d) Calculate the x component of the force exerted by B on C. (e) Calculate the y component of the force exerted by B on C. (f) Sum the two x components from parts (a) and (d) to obtain the resultant x component of the electric force acting on C. (g) Similarly, find the y component of the resultant force vector acting on C. (h) Kind the magnitude and direction of the resultant electric force acting on C.

(a) Calculate the number of electrons in a small, electrically neutral silver pin that has a mass of 10.0 g. Silver has 47 electrons per atom, and its molar mass is 107.87 g/mol. (b) Imagine adding electrons to the pin until the negative charge has the very large value 1.00 mC. How many electrons are added for every 109 electrons already present?

An object has a charge of 35 nC. How many excess protons does it have?

(a) How strong is the attractive force between a glass rod with a 0.700 C charge and a silk cloth with a 0.600 C charge, which are 12.0 cm apart, using the approximation that they act like point charges? (b) Discuss how the answer to this problem might be affected if the charges are distributed over some area and do not act like point charges.

Figure 18.47 shows the electric field lines near two charges q j and g2. What is the ratio of their magnitudes? (b) Sketch the electric field lines a long distance from the charges shown in the figure.

a. Figure 24.22A shows a rod of length L and radius R with excess positive charge Q. The excess charge is uniformly distributed over the entire outside surface of the rod. Write an expression for the surface charge density . Write an expression in terms of for the amount of charge dq contained in a small segment of the rod of length dx. b. Figure 24.22B shows a very narrow rod of length L with excess positive charge Q. The rod is so narrow compared to its length that its radius is negligible and the rod is essentially one-dimensional. The excess charge is uniformly distributed over the length of the rod. Write an expression for the linear charge density . Write an expression in terms of for the amount of charge dq contained in a small segment of the rod of length dx. Compare your answers with those for part (a). Explain the similarities and differences.

Three charged particles are located at the corners of an equilateral triangle as shown in Figure P19.9. Calculate the total electric force on the 7.00-C charge.