A neutral solid metal sphere of radius 0.1 m is at the origin, polarized by a point charge of $6 \times 10^{-8}\ \mathrm{C}$ at location $\langle- 0.3,0,0\rangle\ \mathrm{m} .$ At location $\langle 0,0.07,0\rangle\ \mathrm{m},$ what is the electric field contributed by the polarization charges on the surface of the metal sphere? How do you know?

Applying Concepts Is a tall building more likely to be damaged by an earthquake if the building is on a mountain of granite or in a valley of loose sediment? Explain.

An electric field is applied to a solution containing bromide ions. As a result, the ions move through the solution with an average drift speed of $3.7 \times 10^{-7}\ \mathrm{m} / \mathrm{s}.$ The mobility of bromide ions in solution is $8.1 \times 10^{-8}\ (\mathrm{m} / \mathrm{s}) /(\mathrm{N} / \mathrm{C}) .$ What is the magnitude of the net electric field inside the solution?

A rod is 2.5 m long. Its charge is $-2 \times 10^{-7}\ \mathrm{C}.$ The observation location is 4 cm from the rod, in the midplane. In the expression $E=\frac{1}{4 \pi \varepsilon_{0}} \frac{Q}{r \sqrt{r^{2}+(L / 2)^{2}}}$ what is r in meters?

Which of the following are true? Select all that apply. (1) In equilibrium, there is no net flow of mobile charged particles inside a conductor. (2) The electric field from an external charge cannot penetrate to the center of a block of iron. (3) The net electric field inside a block of aluminum is zero under all circumstances. (4) If the net electric field at a particular location inside a piece of metal is not zero, the metal is not in equilibrium. (5) The net electric field at any location inside a block of copper is zero if the copper block is in equilibrium.

A metal ball with diameter of a half a centimeter and hanging from an insulating thread is charged up with $1 \times 10^{10}$ excess electrons. An initially uncharged identical metal ball hanging from an insulating thread is brought in contact with the first ball, then moved away, and they hang so that the distance between their centers is 20 cm. Calculate the electric force one ball exerts on the other, and state whether it is attractive or repulsive. If you have to make any simplifying assumptions, state them explicitly and justify them.

Blocks A and B are identical metal blocks. Initially block A is neutral, and block B has a net charge of 5 nC. Using insulating handles, the blocks are moved so they touch each other. After touching for a few seconds, the blocks are separated (again using insulating handles). What happened while the blocks were in contact with each other? (1) Protons moved from block B to block A. (2) Positrons moved from block B to block A. (3) Electrons moved from block A to block B. (4) Both protons and electrons moved. (5) No charged particles moved.

A metal sphere of radius 30 cm has a net charge of

$$3.0 \times 10 ^ { - 8 } C$$

. (a) What is the electric field at the sphere's surface? (b) If V = 0 at infinity, what is the electric potential at the sphere 's surface? (c) At what distance from the sphere's surface has the electric potential decreased by 500 V?

In a particular metal, the mobility of the mobile electrons is 0.0077 (m/s)/(N/C). At a particular moment the net electric field everywhere inside a cube of this metal is 0.053 N/C in the +x direction. What is the average drift speed of the mobile electrons in the metal at this instant?

A metal sphere of radius 15 cm has a net charge of $3.0 \times 10^{-8} C$. What is the electric field at the sphere’s surface?

Solve $S = 2 \pi rh$ for $r$

An electron and a neutral carbon atom are initially $1 \times 10^{-6} \mathrm{m}$ apart (about 10000 atomic diameters), and there are no other particles in the vicinity. The polarizability of a carbon atom has been measured to be $\alpha=1.96 \times 10^{-40} \mathrm{C} \cdot \mathrm{m} /(\mathrm{N} / \mathrm{C}).$ Calculate the initial magnitude and direction of the acceleration of the electron. Explain your steps clearly. Pay particular attention to clearly defining your algebraic symbols. Don't put numbers into your calculation until the very end.

The mobility of $\mathrm{Na}^{+}$ ions in water is $5.2 \times 10^{-8}\ (\mathrm{m} / \mathrm{s}) /(\mathrm{N} / \mathrm{C}).$ If an electric field of 2400 N/C is maintained in the fluid, what is the drift speed of the sodium ions?

If the distance between a neutral atom and a point charge is tripled, by what factor does the force on the atom by the point charge change? Express your answer as a ratio: new force/original force.