Physics-Coulomb's Law and electrostatics

Objectives:

Use the inverse square relationship between force and charge separation (distance) to determine the relative force between charges at various separations.

Know the basic precautions for lightning safety.

4

These are some of the terms associated with the study of electric charges. Find which terms match with which definitions. Keep at it until you get green dots for each set.

Draggable item		Corresponding Item
Coulomb's law		the space around a charge that is influenced by that charge
static electricity		an equation that relates the strength of the force exerted by one charge on another with respect to the distance between them; an inverse square law
electric field		the study of phenomena created by electric charges at rest
electrostatics		electricity held in place by a material with an electric charge

1

A large electrostatic generator is commonly called a(n) _____.

lightning rod

force field

Van de Graaff generator

electroscope

1

Select all that apply.
How does an electrostatic generator operate?

Electrons are transferred to a metallic sphere.

A motor drives a belt moving through magnets.

An electric motor causes electricity to flow through a moving belt.

Electrons are stripped off a wool pad.

1

What occurs when charges build up on a surface?

They cause interacting materials to move in the same direction.

There is no affect on the other charges around them.

The charges create an electric field.

They form a strength independent of the distance of the charges.

1

Charge q is 1 unit of distance away from the source charge S. Charge p is three times farther away than q. The force of S on p is ______ the force of S on q.

one-ninth

one-third

three times

Create the following scenarios using the Coulomb's Law PHeT simulation and then answer the question. Make sure to check the force values box. Copy this link and paste into browser to access the simulation: https://phet.colorado.edu/sims/html/coulombs-law/latest/coulombs-law_en.html

The crash dummies either have to push or pull the charged objects to keep them at a set distance. The force above the object shows how much force is needed in the push or pull.

1

Set both charge 1 and charge 2 to -4 microcoulombs (the only charge available). Do the dummies push or pull?

push

pull

1

Do the charges attract or repel each other?

attract

repel

1

Leave charge 1 at -4 microcoulombs and set charge 2 to 4 microcoulombs. Do the dummies push or pull?

push

pull

1

Do the charges attract or repel each other?

attract

repel

1

Place charge 1 on the 4 cm mark and charge 2 on the 6 cm mark. What is the force value of charge 2?

1

Now double the distance between the charges by moving charge 2 to the 8 cm mark. What is the force value of charge 2?

1

Compare the value of 4 cm apart to 2 cm apart? (divide answer to 11 by the answer to 10). Rounded to the tenth (0.1), what did you get?

2

4

0.5

0.25

1

Explain how the answer to twelve follows or does not follow Coulomb's Law. You might want to scroll up and look at the chart and the summary under it.

1

Who invented lightning rods to protect buildings from lightning?

William Gilbert

Benjamin Franklin

Van de Graaff

Charles de Coulomb

1

An atmospheric discharge of static electricity is called _____.

electrostatic energy

a current

a watt

lightning

2

. Three particles are located on a coordinate system. An electron is located at the origin, a proton is located at (0, 1), and an electron is located at (1, 0). What is the direction of the net electrostatic force on the electron located at the origin?

To the right on the coordinate plane

At an angle of 45° (up and to the right on the coordinate plane)

Up on the coordinate plane

At an angle of 135° (up and to the left on the coordinate plane)

2

. An electron and a proton are separated by 1.50 × 10-10 m. If they are released, which one will accelerate at a greater rate, and what is the magnitude of that initial acceleration? (m_e=9.1x10 ^-31kg, m_p=1.67x 10^-27kg )

The electron; 1.12 × 10²² m/s²

The proton; 1.12 × 10²² m/s²

The electron; 6.13 × 10¹⁸ m/s²

The proton; 6.13 × 10¹⁸ m/s2

2

A hydrogen nucleus (charge +e) and a beryllium nucleus (charge +4e) experience a force, F. Given k as the Coulomb’s law constant, which of the following is the distance between the nuclei?(solve for d)

1

Three identical conducting spheres are on insulated stands and are not touching one another initially. Sphere A has a charge of +10 µC, Sphere B has a charge of -6 µC, and Sphere C has a charge of -4 µC. Sphere A contacts Sphere B, and they are separated. Next, Sphere B contacts Sphere C, and they are separated. What is the final charge on Sphere C?

-1 µC

-2 µC

0 µC

+2 µC

1

A helium nucleus (charge +2e) and a hydrogen nucleus (charge +e) are initially separated a certain distance. If the helium nucleus is held in place, describe the motion of the hydrogen nucleus.

Physics-Coulomb's Law and electrostatics

These are some of the terms associated with the study of electric charges. Find which terms match with which definitions. Keep at it until you get green dots for each set.

A large electrostatic generator is commonly called a(n) _____.

Select all that apply.How does an electrostatic generator operate?

What occurs when charges build up on a surface?

Charge q is 1 unit of distance away from the source charge S. Charge p is three times farther away than q. The force of S on p is ______ the force of S on q.

Set both charge 1 and charge 2 to -4 microcoulombs (the only charge available). Do the dummies push or pull?

Do the charges attract or repel each other?

Leave charge 1 at -4 microcoulombs and set charge 2 to 4 microcoulombs. Do the dummies push or pull?

Do the charges attract or repel each other?

Place charge 1 on the 4 cm mark and charge 2 on the 6 cm mark. What is the force value of charge 2?

Now double the distance between the charges by moving charge 2 to the 8 cm mark. What is the force value of charge 2?

Compare the value of 4 cm apart to 2 cm apart? (divide answer to 11 by the answer to 10). Rounded to the tenth (0.1), what did you get?

Explain how the answer to twelve follows or does not follow Coulomb's Law. You might want to scroll up and look at the chart and the summary under it.

Who invented lightning rods to protect buildings from lightning?

An atmospheric discharge of static electricity is called _____.

. Three particles are located on a coordinate system. An electron is located at the origin, a proton is located at (0, 1), and an electron is located at (1, 0). What is the direction of the net electrostatic force on the electron located at the origin?

. An electron and a proton are separated by 1.50 × 10-10 m. If they are released, which one will accelerate at a greater rate, and what is the magnitude of that initial acceleration? (me =9.1x10 -31kg, mp =1.67x 10-27kg )

A hydrogen nucleus (charge +e) and a beryllium nucleus (charge +4e) experience a force, F. Given k as the Coulomb’s law constant, which of the following is the distance between the nuclei?(solve for d)

A helium nucleus (charge +2e) and a hydrogen nucleus (charge +e) are initially separated a certain distance. If the helium nucleus is held in place, describe the motion of the hydrogen nucleus.

These are some of the terms associated with the study of electric charges. Find which terms match with which definitions. Keep at it until you get green dots for each set.

A large electrostatic generator is commonly called a(n) _____.

Select all that apply.How does an electrostatic generator operate?

What occurs when charges build up on a surface?

Charge q is 1 unit of distance away from the source charge S. Charge p is three times farther away than q. The force of S on p is ______ the force of S on q.

Set both charge 1 and charge 2 to -4 microcoulombs (the only charge available). Do the dummies push or pull?

Do the charges attract or repel each other?

Leave charge 1 at -4 microcoulombs and set charge 2 to 4 microcoulombs. Do the dummies push or pull?

Do the charges attract or repel each other?

Place charge 1 on the 4 cm mark and charge 2 on the 6 cm mark. What is the force value of charge 2?

Now double the distance between the charges by moving charge 2 to the 8 cm mark. What is the force value of charge 2?

Compare the value of 4 cm apart to 2 cm apart? (divide answer to 11 by the answer to 10). Rounded to the tenth (0.1), what did you get?

Explain how the answer to twelve follows or does not follow Coulomb's Law. You might want to scroll up and look at the chart and the summary under it.

Who invented lightning rods to protect buildings from lightning?

An atmospheric discharge of static electricity is called _____.

. Three particles are located on a coordinate system. An electron is located at the origin, a proton is located at (0, 1), and an electron is located at (1, 0). What is the direction of the net electrostatic force on the electron located at the origin?

. An electron and a proton are separated by 1.50 × 10-10 m. If they are released, which one will accelerate at a greater rate, and what is the magnitude of that initial acceleration? (me =9.1x10 -31kg, mp =1.67x 10-27kg )

A hydrogen nucleus (charge +e) and a beryllium nucleus (charge +4e) experience a force, F. Given k as the Coulomb’s law constant, which of the following is the distance between the nuclei?(solve for d)

A helium nucleus (charge +2e) and a hydrogen nucleus (charge +e) are initially separated a certain distance. If the helium nucleus is held in place, describe the motion of the hydrogen nucleus.

Select all that apply.
How does an electrostatic generator operate?

. An electron and a proton are separated by 1.50 × 10-10 m. If they are released, which one will accelerate at a greater rate, and what is the magnitude of that initial acceleration? (m_e=9.1x10 ^-31kg, m_p=1.67x 10^-27kg )

Select all that apply.
How does an electrostatic generator operate?

. An electron and a proton are separated by 1.50 × 10-10 m. If they are released, which one will accelerate at a greater rate, and what is the magnitude of that initial acceleration? (m_e=9.1x10 ^-31kg, m_p=1.67x 10^-27kg )