Record data from the values to the right of the world in the table below. Take at least 5 data points. Click on the green + in the bottom row to add more rows of data.
Overview
Teacher designed unit
Standards
Computational Thinking in STEM
- Data Practices
- Creating Data
- Modeling and Simulation Practices
- Using Computational Models to Understand a Concept
Credits
Unit designed by Neil Schmidgall a teacher at Glenbrook South.
Activities
- 1. Getting familiar with the model
- 2. Part A: Source Charge
- 3. Part B: Point Charge
- 4. Part C: Distance
- 5. Part D: Equations
- 6. Part E: Conclusions about the Electric Field
Student Directions and Resources
A positive charge, Q, is located at the bottom center of the Netlogo World. This charge is creating an Electric Field in the space around it. Another electric charge, q, is shown near the center of the world positioned in this Electric Field. The green Force vector at the top shows the force on the charge, q, due to the field and the yellow field vector at the bottom shows the direction and magnitude of the electric field where the charge in the field, q, is located.
1. Getting familiar with the model
Hit Setup and Go for the model below. Move your cursor around in the space surrounding the positive Source Charge, Q, located at the bottom center of the NetLogo World. The green Force vector at the top shows the force, Fe, on the charge, q, due to the field, and the yellow field vector at the bottom shows the direction and magnitude of the Electric Field, E, where the charge in the field, q, is located. The values listed to the right of the World are recording values related to the situation set up in the World.
2. Part A: Source Charge
The values listed to the right of the World are recording values related to the situation set up in the World.
Find the effect on the Electrostatic Force value on the charge, q, and the Electric Field value at the position of the charge, q, if the source charge, Q, is altered. Take data by changing the value of the source charge, Q. Click on Setup to get the values to the right of the World.
Question 2.1
Question 2.2
Do a power regression on the data to determine the dependence of Electrostatic Force and Electric Field on the source charge, Q.
Electrostatic Force, Fe, is dependent on Q to what power?
-2
-1.5
-1
-0.5
0
0.5
1
1.5
2
-1.5
-1
-0.5
0
0.5
1
1.5
2
Question 2.3
Electric Field, E, is dependent on Q to what power?
-2
-1.5
-1
-0.5
0
0.5
1
1.5
2
-1.5
-1
-0.5
0
0.5
1
1.5
2
3. Part B: Point Charge
The values listed to the right of the World are recording values related to the situation set up in the World.
Find the effect on the Electrostatic Force value on the charge, q, and the Electric Field value at the position of the charge, q, if the charge in the field, q, is altered. Take data by changing the value of the charge in the field, q. Click on Setup to get the values to the right of the World.
Question 3.1
Record data from the values to the right of the world in the table below. Take at least 5 data points. Click on the green + in the bottom row to add more rows of data.
Question 3.2
Do a power regression on the data to determine the dependence of Electrostatic Force and Electric Field on the point charge in the field, q. Electrostatic Force, Fe, is dependent on q to what power?
-2
-1.5
-1
-0.5
0
0.5
1
1.5
2
-1.5
-1
-0.5
0
0.5
1
1.5
2
Question 3.3
Electric Field, E, is dependent on q to what power?
-2
-1.5
-1
-0.5
0
0.5
1
1.5
2
-1.5
-1
-0.5
0
0.5
1
1.5
2
4. Part C: Distance
The values listed to the right of the World are recording values related to the situation set up in the World.
Find the effect on the Electrostatic Force value on the charge, q, and the Electric Field value at the position of the charge, q, if the distance, r, of q from the source charge Q, is altered. Take data by changing the position of the charge, q, in the field.
Do this by
1) clicking on Setup,
2) clicking on Go, and
3) moving your mouse around in the World to change the location of the point charge.
Question 4.1
Record data from the values to the right of the world in the table below. Take at least 5 data points. Click on the green + in the bottom row to add more rows of data.
Question 4.2
Do a power regression on the data to determine the dependence of Electrostatic Force and Electric Field on the distances between charges, r.
Electrostatic Force, Fe, is dependent on r to what power?
-2
-1.5
-1
-0.5
0
0.5
1
1.5
2
-1.5
-1
-0.5
0
0.5
1
1.5
2
Question 4.3
Electric Field, E, is dependent on r to what power?
-2
-1.5
-1
-0.5
0
0.5
1
1.5
2
-1.5
-1
-0.5
0
0.5
1
1.5
2
5. Part D: Equations
Use the data that you have collected to write the equations of proportionality for force and electric field in the blanks below using Q, q, and r.
Question 5.1
It is fortunate for us that physics allows us to formulate relationships between variables (equations) given a moderately low number of data points. Insert the values in the table below that would satisfy the equation solving for Electrostatic Force using your previous results. k is a constant to make the relationship an equality.
Question 5.2
It is fortunate for us that physics allows us to formulate relationships between variables (equations) given a moderately low number of data points. Insert the values in the table below that would satisfy the equation solving for Electric Field using your previous results. k is a constant to make the relationship an equality.
Question 5.3
There is also a way to reason through the equations when knowing just the factor of change. For instance, if you double the charge, q, you just tested, can you predict the effect on force by reasoning through the equation you've found and determining what would happen if a doubling occurs, or a tripling, or a quadrupling? In other words, could you tell me what factor the force will change by given you are going to double the charge in the field? Make a prediction below by picking a factor by which the force, Fe, on charge, q, will change when the magnitude of the charge, q, is doubled.
2 to a power of 2
2 to a power of 1
2 to a power of 0.5
2 to a power of 0
2 to a power of -0.5
2 to a power of -1
2 to a power of -2
2 to a power of 1
2 to a power of 0.5
2 to a power of 0
2 to a power of -0.5
2 to a power of -1
2 to a power of -2
Question 5.4
Make a prediction below by picking a factor by which the force, Fe, on charge, q, will change when the magnitude of the source charge, Q, is doubled.
2 to a power of 2
2 to a power of 1
2 to a power of 0.5
2 to a power of 0
2 to a power of -0.5
2 to a power of -1
2 to a power of -2
2 to a power of 1
2 to a power of 0.5
2 to a power of 0
2 to a power of -0.5
2 to a power of -1
2 to a power of -2
Question 5.5
Make a prediction below by picking a factor by which the force, Fe, on charge, q, will change when the distance, r, between charges, q and Q, is doubled.
2 to a power of 2
2 to a power of 1
2 to a power of 0.5
2 to a power of 0
2 to a power of -0.5
2 to a power of -1
2 to a power of -2
2 to a power of 1
2 to a power of 0.5
2 to a power of 0
2 to a power of -0.5
2 to a power of -1
2 to a power of -2
Question 5.6
Make a prediction below by picking a factor by which the electric field, E, at the location of charge, q, will change when the magnitude of the charge, q, is doubled.
2 to a power of 2
2 to a power of 1
2 to a power of 0.5
2 to a power of 0
2 to a power of -0.5
2 to a power of -1
2 to a power of -2
2 to a power of 1
2 to a power of 0.5
2 to a power of 0
2 to a power of -0.5
2 to a power of -1
2 to a power of -2
Question 5.7
Make a prediction below by picking a factor by which the electric field, E, at the location of charge, q, will change when the magnitude of the source charge, Q, is doubled.
2 to a power of 2
2 to a power of 1
2 to a power of 0.5
2 to a power of 0
2 to a power of -0.5
2 to a power of -1
2 to a power of -2
2 to a power of 1
2 to a power of 0.5
2 to a power of 0
2 to a power of -0.5
2 to a power of -1
2 to a power of -2
Question 5.8
Make a prediction below by picking a factor by which the electric field, E, at the location of charge, q, will change when the distance, r, from the source charge, Q, is doubled.
2 to a power of 2
2 to a power of 1
2 to a power of 0.5
2 to a power of 0
2 to a power of -0.5
2 to a power of -1
2 to a power of -2
2 to a power of 1
2 to a power of 0.5
2 to a power of 0
2 to a power of -0.5
2 to a power of -1
2 to a power of -2
6. Part E: Conclusions about the Electric Field
Question 6.1
Click on Setup in the model above. The gray lines in the space are manmade constructs called electric field lines. What is the only factor that changes the number of lines, and therefore the angular spacing between lines, in the area where the field is located?
Question 6.2
How can you determine the relative strength of the electric field compared to other locations by examining just the lines and their relationship to each other?
Question 6.3
How does changing the point charge, q, value in the field affect the electric field, E, created by the source charge?
Question 6.4
How does changing the point charge, q, in the field from positive to negative affect the magnitude and direction of the force vector on that charge, q?
