Electrostatic Force

Physics 5 (A &C)

Coulombs Law Introduction

Multiple Choice

Which formula is the correct equation for Coulombs Law?

Multiple Choice

What does the k stand for in this formula?

• Coulomb constant

• Electric Force

• Charge on object 1

• Charge on object 2

• distance between the centers of the charges of mass

Multiple Choice

What does the q1 stand for in this formula?

• Coulomb constant

• Electric Force

• Charge on object 1

• Charge on object 2

• distance between the centers of the charges of mass

Multiple Choice

What does the q2 stand for in this formula?

• Coulomb constant

• Electric Force

• Charge on object 1

• Charge on object 2

• distance between the centers of the charges of mass

Multiple Choice

What does  $$r^2$$  the stand for in this formula?

• Coulomb constant

• Electric Force

• Charge on object 1

• Charge on object 2

• distance between the centers of the charges of mass (squared)

Multiple Choice

What does the Fe stand for in this formula?

• Coulomb constant

• Electric Force

• Charge on object 1

• Charge on object 2

• distance between the centers of the charges of mass (squared)

Multiple Select

For Coulombs Law, r is NOT... you may choose more than one answer

• the radius

• the distance between the center of mass

• the distance between the center of the charges of mass

Multiple Choice

Which is the stronger force: the force of gravity acting on the attracted object or the electric force acting on the attracted object.

• force of gravity

• the electric force

Multiple Choice

(Warning! The numbers here are slightly different than the video)

Two equal magnitude point charges are located 2.5 meters apart. If the magnitudes of their charges are both 15.0 C, however one is negative and one is positive.

Assume q1 is positive and q2 is negative.

What is the charge of q1?

• 15.0 C

• -15.0 C

• 2.5 m

• 6.25 m

• 8.99E9

Multiple Choice

(Warning! The numbers here are slightly different than the video)

Two equal magnitude point charges are located 2.5 meters apart. If the magnitudes of their charges are both 15.0 C, however one is negative and one is positive.

Assume q1 is positive and q2 is negative.

What is the charge of q2?

• 15.0 C

• -15.0 C

• 2.5 m

• 6.25 m

• 8.99E9

Multiple Choice

(Warning! The numbers here are slightly different than the video)

Two equal magnitude point charges are located 2.5 meters apart. If the magnitudes of their charges are both 15.0 C, however one is negative and one is positive.
Assume q1 is positive and q2 is negative.
What is the magnitude of r ?

• 15.0 C

• -15.0 C

• 2.5 m

• 6.25 m

• 8.99E9

Multiple Choice

(Warning! The numbers here are slightly different than the video)

Two equal magnitude point charges are located 2.5 meters apart. If the magnitudes of their charges are both 15.0 C, however one is negative and one is positive.
Assume q1 is positive and q2 is negative.
What is the magnitude of  $$r^2$$  ?

• 15.0 C

• -15.0 C

• 2.5 m

• 6.25 m

• 8.99E9

Multiple Choice

(Warning! The numbers here are slightly different than the video)

Two equal magnitude point charges are located 2.5 meters apart. If the magnitudes of their charges are both 15.0 C, however one is negative and one is positive.
Assume q1 is positive and q2 is negative.
What do we use for coulombs constant (k) ?

• 15.0 C

• -15.0 C

• 2.5 m

• 6.25 m

• 8.99E9

Multiple Choice

In the video, it was decided that if your answer turned out negative, it indicated the force was an _______ force.

• attractive force

• repulsive force

Multiple Choice

If you have two positive charges, will your answer be positive or negative, and therefore repel or attract each other?

• positive & attract

• positive & repel

• negative & attract

• negative & repel

Multiple Choice

If you have two negative charges, will your answer be positive or negative, and therefore repel or attract each other?

• positive & attract

• positive & repel

• negative & attract

• negative & repel

Multiple Choice

If you have one negative charge and one positive charge, will your answer be positive or negative, and therefore repel or attract each other?

• positive & attract

• positive & repel

• negative & attract

• negative & repel

1. Variables in the problem that stay the same are represented with a 1

2. Variables that increase or decrease are represented with the factor of change

3. Ex. How would the electrostatic force change if the charge of one object is quadrupled?

​

Proportional Thinking

Example.

How would the electrostatic force between two objects change if one of the charges triples?

​Try it out...watch the video to check your response!

Example.

How much stronger is the electrostatic force if the distance between two charged objects is cut in half?

​Try it out...watch the video to check your response!

Example.

How would the electrostatic force between charged objects change if they go from being 1m apart to 3m apart?

​Try it out...watch the video to check your response!

Example.

How would the electrostatic force between charged objects change if the magnitude of both objects triples and the distance doubles?

​Try it out...watch the video to check your response!

Multiple Choice

When distance increases, electrostatic force ____________; we call this relationship ____________ proportional

• decreases;directly
• decreases;inversely
• increases;inversely
• increases;directly

Multiple Choice

If the distance doubles, what happens to the force?

• Reduced by half
• Reduced by 1/4
• Stays the same
• Quadruples

Multiple Choice

Which setup of charged particles shown below has the two exert the most force on one another?

Multiple Choice

If each of the charges doubles, what happens to the force?

• Quadruples
• Doubles
• Stays the same
• Reduced by half

Lesson P.5 (A & C )

Electrostatic Force

Multiple Choice

Objects with opposite charges produce an ________ force.

• repulsive (moves away)

• attractive (moves towards)

Multiple Choice

Objects with the same charges produce a ________ force.

• repulsive (repel away)

• attractive (move towards)

Multiple Choice

The larger the charges, the ______ the force between them.

• greater

• less

Multiple Choice

The greater the distance between the charged objects , the ______ the force between them.

• smaller

• greater

Multiple Choice

Who founded the electrostatics theory which is now called Coulombs Law?

• Charles Coulomb

• Michael Faraday

• Dr. Orested

Multiple Choice

"Electricity is just a stream of electrons trying to get from a ______ place to a _____ place."

• negative to positive

• positive to negative

• negative to negative

• positive to positive

Multiple Choice

True or False: All magnets are have a positive and negative pole.

• True

• False

Multiple Choice

True or False: All magnets are only made of iron.

• True

• False

Multiple Select

What is a force? (Check all that apply)

• a push or a pull

• an attraction/repulsion between objects

• "...a mysterious energy field created by life that binds the galaxy together." (Star Wars)

Multiple Choice

If a "force" is an attraction that pulls, and a repulsion that pushes away, then what is an electromagnetic force?

• it is a force that is made from running electricity through a wire.

• doesn't exist

• comes from using a magnet

Multiple Select

Electromagnetic Force acts on objects that have an electric charge.

What are the two charges found in electrostatics? Choose the two that apply.

• Positive

• Negative

• Neutral

• None of the above

Multiple Choice

It seems that every time the electrical current was flowing from

the battery, the needle on the compass was being deflected at right angles.

Which fundamental force was responsible for this observation?

• electromagnetic force

• gravity

• proton force

• Neutral force