Physics B

Two identical metal balls A and B are mounted on insulating rods. Ball A has a charge of +2q, and ball B is initially uncharged. Then ball A is touched to ball B. What is the resulting charge on ball A?

+q/4

Three point charges are arranged in a line. Charges q3 = +5.00 nC and is located at the origin. Charge q2 = -3.00 nC and is located at x = +4.00. Charge q1 is located at x = +2.00 cm. What is the magnitude of q1 if the net force on q3 is zero?

0.750 nC

The repulsive force between two protons has a magnitude of 2.00 N. What is the distance between them?

1.07 x 10^-14 m

How many electrons must be added to a neutral object to provide it a charge of -2.4 uC?

1.5 x 10^13 electrons

A chlorine atom has 17 protons and 17 electrons. How many protons and electrons make up a chlorine ion of -1 charge?

17 protons, 18 electrons

In an experiment in space, one proton is held in a fixed position. Then a second proton is released from rest at a distance of 2.50 mm from the fixed proton. What is the initial acceleration of the proton after it is released?

2.20 x 10^4 m/s^2

An electron is separated from a proton by a distance of 1.00 x 10^-10 m. What is the magnitude of the electron force between them?

2.30 x 10^-8 N

Two point charges are located on the y-axis as follows: charge q1 = -1.50 nC at y = -0.600 m, and charge q2 = +3.20 nC at the origin (y=0) What is the magnitude of the net force exerted by these two charges on a third charge q3 = +5.00 nC located at y = -0.400 m?

2.59 x 10^-6 N

In the nucleus of an atom, two protons are separated by a distance of 1 x 10^-15 m. What is the magnitude of the electric force between them?

230 N

As shown in the diagram, three equal charges are spaced evenly in a row. The magnitude of each charge is +2e, and the distance between two adjacent charges is 1.50 nm. Then the central charge is displaced 0.350 nm to the right while the other two charges are held in place. After the displacement, what is the magnitude and direction of the net force that the outer two charges exert on the central charge?

4.27 x 10^-10 N to the left

Two small spheres are placed 20.0 cm apart and have equal negative charge. The force of repulsion between them is 4.57 x 10^-21 N. How many excess electrons are present on each sphere?

891

During the polarization of an object, what happens to the charges that the object carries?

Positive and negative charges become separated

In every neutral atom, which two types of particles are found in equal number?

Protons and electrons

A scientist wants to charge an object by induction. Which statement best explains why the object should be insulated?

The charge can shift throughout the object, but new charges cannot enter it

A neutral aluminum rod is at rest on a foam insulating base. A negatively charged balloon is brought near one end of the rod but not in direct contact with it. In what way, if any, will the charges in the rod be affected?

The charges will become polarized with a positive zone near the balloon

A negatively charged rod is brought near a metal ball on an insulating stand. A ground wire is then attached to the ball and removed. For the positive charges to spread evenly through the ball, what must happen next?

The rod must be pulled away from the ball

Which statement is part of the principle of conservation of charge?

The total charge of any closed system is constant

Two small identical balls A and B are held a distance r apart on a frictionless surface, with r very large compared with the size of the balls. Ball A has a net charge of 2q; ball B has a net charge of q. The balls are released at the same instant and begin to move together. Which characteristics describe the magnitudes of their accelerations over time?

equal and increasing

A positive ion forms when an atom

loses one or more electrons

A stream of negatively charged particles is pulled toward a steel plate. The plate must be

positively charged