Name: Date:
Student Exploration: Coulomb Force (Static)
Directions: Follow the instructions to go through the simulation. Respond to the questions and
prompts in the orange boxes.
Vocabulary: Coulomb’s law, electrostatic force, vector
Prior Knowledge Questions (Do these BEFORE using the Gizmo.). Have you ever taken clothes out of
the dryer and found a sock stuck to your underwear? Static cling is an example of electrostatic forces, or
the forces that exist between charged objects.
1. How do you think the sock and underwear became charged?
They probably became charged because they were rubbing together in the dryer.
2. Suppose two socks acquire the same charge. Do you think they would stick together? Explain:
They would not stick together because objects with same signs repel each other.
Gizmo Warm-up
As clothes are tumbled in a dryer, electrons are rubbed off
some items, giving them a positive charge, and deposited
on other items, giving them a negative charge. These
charged items exert electrostatic forces on one another.
You can explore these forces with the Coulomb Force
(Static) Gizmo.
In its initial settings, the Gizmo shows two objects that each have a charge (q) of 10.0 × 10-4 C (coulombs).
Turn on the Show force vector checkboxes for objects A and B. The arrows coming from each object are
vectors that represent the electrostatic force. The direction and length of each vector show the direction
and magnitude (strength) of each force.
1. Are the vectors for objects A and B pointing together or away from each other?
Away from each other.
2. Are objects A and B attracted together or repelled apart?
Repelled apart.
3. Compare the lengths of the vectors. What do you notice?
The vectors lengths are equal.
Reproduction for educational use only. Public sharing or posting prohibited. © 2021 ExploreLearning™ All rights reserved
, Get the Gizmo ready:
Activity A:
● Turn on Show grid. Place object A on the x-axis
at -5 and object B on the x-axis at +5.
The effect of
● Check that Show force vector is turned on for
charge
each object.
Question: How does charge affect the strength of the electrostatic force?
1. Observe: You can change the charge of each object by entering the desired value in the qA and qB
boxes. Observe the force vectors for each of the situations listed in the table below. Based on the force
vectors, state whether the objects are repelled from one another, attracted to one another, or if there is
no force at all.
qA qB Attraction, repulsion, or no force?
1.0 × 10-4 C 1.0 × 10-4 C repulsion
-1.0 × 10-4 C 1.0 × 10-4 C attraction
-1.0 × 10-4 C -1.0 × 10-4 C repulsion
1.0 × 10-4 C 0.0 × 10-4 C no force
2. Make a rule: Complete the following sentences with the words “attract,” “repel,” or “zero.”
When the charges are the same, the two objects repel one another.
When the charges are opposite, the two objects attract one another.
When one of the objects has no charge, the resulting force is zero.
3. Predict: How do you think the magnitude of the electrostatic force between two objects will change if
the charge of each object was doubled?
I think the magnitude will double as well.
4. Measure: Turn on Show vector notation for both objects. Set the charge of objects A and B to 1.0 ×
10-4 C. The force on object A is now -0.90i + 0j N. That means that the force is
-0.90 N in the x direction and 0 N in the y direction.
A. What is the magnitude of the force on object A? |FA| = 0.90 N
B. What is the magnitude of the force on object B? |FB| = 0.90 N
C. The force on object A is negative. What does this indicate about the direction of the force?
it is going towards the negative direction, or to the left
Reproduction for educational use only. Public sharing or posting prohibited. © 2021 ExploreLearning™ All rights reserved
Student Exploration: Coulomb Force (Static)
Directions: Follow the instructions to go through the simulation. Respond to the questions and
prompts in the orange boxes.
Vocabulary: Coulomb’s law, electrostatic force, vector
Prior Knowledge Questions (Do these BEFORE using the Gizmo.). Have you ever taken clothes out of
the dryer and found a sock stuck to your underwear? Static cling is an example of electrostatic forces, or
the forces that exist between charged objects.
1. How do you think the sock and underwear became charged?
They probably became charged because they were rubbing together in the dryer.
2. Suppose two socks acquire the same charge. Do you think they would stick together? Explain:
They would not stick together because objects with same signs repel each other.
Gizmo Warm-up
As clothes are tumbled in a dryer, electrons are rubbed off
some items, giving them a positive charge, and deposited
on other items, giving them a negative charge. These
charged items exert electrostatic forces on one another.
You can explore these forces with the Coulomb Force
(Static) Gizmo.
In its initial settings, the Gizmo shows two objects that each have a charge (q) of 10.0 × 10-4 C (coulombs).
Turn on the Show force vector checkboxes for objects A and B. The arrows coming from each object are
vectors that represent the electrostatic force. The direction and length of each vector show the direction
and magnitude (strength) of each force.
1. Are the vectors for objects A and B pointing together or away from each other?
Away from each other.
2. Are objects A and B attracted together or repelled apart?
Repelled apart.
3. Compare the lengths of the vectors. What do you notice?
The vectors lengths are equal.
Reproduction for educational use only. Public sharing or posting prohibited. © 2021 ExploreLearning™ All rights reserved
, Get the Gizmo ready:
Activity A:
● Turn on Show grid. Place object A on the x-axis
at -5 and object B on the x-axis at +5.
The effect of
● Check that Show force vector is turned on for
charge
each object.
Question: How does charge affect the strength of the electrostatic force?
1. Observe: You can change the charge of each object by entering the desired value in the qA and qB
boxes. Observe the force vectors for each of the situations listed in the table below. Based on the force
vectors, state whether the objects are repelled from one another, attracted to one another, or if there is
no force at all.
qA qB Attraction, repulsion, or no force?
1.0 × 10-4 C 1.0 × 10-4 C repulsion
-1.0 × 10-4 C 1.0 × 10-4 C attraction
-1.0 × 10-4 C -1.0 × 10-4 C repulsion
1.0 × 10-4 C 0.0 × 10-4 C no force
2. Make a rule: Complete the following sentences with the words “attract,” “repel,” or “zero.”
When the charges are the same, the two objects repel one another.
When the charges are opposite, the two objects attract one another.
When one of the objects has no charge, the resulting force is zero.
3. Predict: How do you think the magnitude of the electrostatic force between two objects will change if
the charge of each object was doubled?
I think the magnitude will double as well.
4. Measure: Turn on Show vector notation for both objects. Set the charge of objects A and B to 1.0 ×
10-4 C. The force on object A is now -0.90i + 0j N. That means that the force is
-0.90 N in the x direction and 0 N in the y direction.
A. What is the magnitude of the force on object A? |FA| = 0.90 N
B. What is the magnitude of the force on object B? |FB| = 0.90 N
C. The force on object A is negative. What does this indicate about the direction of the force?
it is going towards the negative direction, or to the left
Reproduction for educational use only. Public sharing or posting prohibited. © 2021 ExploreLearning™ All rights reserved
