The Arizona STEM Acceleration Project
Electromagnetic Forces
Electromagnetic Forces
A 7th Grade STEM Lesson
Jamie Rapkiewcz, M.Ed.
May 2023
Notes for Teachers
It is important to test the materials first before doing the activities with students. Using a battery holder and attaching the wires to the magnet wire with connecting wires makes investigations safer.
Alternatively, I found success in purchasing electromagnet refill kits for the initial investigation instead of creating my own.
Magnet wire and the wires with the alligator clips can burn out. when testing a system it is helpful to use a multimeter tool to determine which components of the system are not working properly.
SAFETY: if the wires are hot disconnect the power source
List of Materials
Standards
Science
7.P2U1.1 Collect and analyze data demonstrating how electromagnetic forces can be attractive or repulsive and can vary in strength.
7.P2U1.2 Develop and use a model to predict how forces act on objects at a distance.
SEPs: Develop and use models, Analyze and interpret data
CCS: Patterns, Systems and System models, Matter and Energy
Math
7.RP.A.2: Recognize and represent proportional relationships between quantities.
a. Decide whether two quantities are in a proportional relationship (e.g., by testing for equivalent ratios in a table or graphing on a coordinate plane and observing whether the graph is a straight line through the origin).
Objective(s):
Day 1: Design an investigation to determine if electromagnetic forces are attractive.
Day 2: Collect and analyze data demonstrating how electromagnetic forces can be attractive or repulsive and can vary in strength.
Day 3: Design an electromagnet crane that is able to collect more material than the initial electromagnet.
Day 4: Analyze data to determine how electromagnetic forces can vary in strength.
Day 5: Draw a model to show how electromagnetic forces are attractive or repulsive and includes factors that cause it to vary in strength.
Agenda
Day 1-Anchor Phenomenon and driving question board (Engage)
Electromagnet Investigation 1 (Explore)
Day 2 Electromagnet Investigation debrief (Explain)
Day 3 Electromagnetic Crane Design (Elaborate)
Day 4 Electromagnetic Crane debrief (Elaborate/Explain)
Day 5 Electromagnet Assessment (Evaluate)
Some common questions:
What is an electromagnet? How does it attract and repel? How does it cause the liquid to move like that?
Share your questions with your group and then choose your group’s 3 favorite questions and add them to the question board.
Hands-on Activity Instructions
Electromagnet Materials Practice 1
Procedures:
1. Leaving 3 to 4 inches at either end of the wire, wrap the wire around the straw. Attempt to keep the wire all together in a small area.
2. Using the scissors, cut off the straw before and after the wire coil.
3. Using the blade of the wire strippers, strip the coating off the wire ends.
4. Spread loose staples out on a table.
5. Using alligator clips, connect the wire to the terminals of a battery.
6. Try using the coil, which is now an electromagnet, to pick up the staples. Record how many staples you were able to lift at once: _______
7. Disconnect the battery.
8. Now, slip the nail into the straw sleeve so that the wire coil is now positioned around the nail.
9. Reconnect the battery.
10. Attempt to pick up the staples again. Record how many staples were picked up this time: _______
What factors could affect the strength of the electromagnet?
-Distance between coils, strength of battery, number of coils
MATH
Graph the data and determine if the variable you tested affects the strength of the electromagnetic force
What factors affect the strength of electromagnetic force?
Image from: https://brainly.com/question/16052649
Hands-on Activity Instructions
Day 2:
In groups of 4 students will analyze their lab data and identify how the different factors (distance between coils, number of coils, voltage of battery) affect the strength of the electromagnetic field.
After the students viewed what other groups investigated and their analysis, the teacher will lead the group in a discussion to understand how electricity and magnetism work together and create electromagnetic fields. They will construct an explanation of factors that influence the strength of an electromagnet.
Explain Electromagnet video here
Explain by recreating a demo to show electromagnetic fields.
Afterwards, have groups process their understanding of how an electromagnet works.
Does __________affect the strength of an electromagnet?
Experimental Design
Condition 1:
Condition 2:
Condition 3:
Investigation Data | |||
| | | |
| | | |
Explanation:
The investigation showed that ___________
affects _______________.
The evidence that supports this is ________________________________________________________________________
We learned ____________ this is supported by _____________________.
Example of what students might write on their whiteboard.
Student presentation prompts can support students in discussion. If needed students can use these sentence starters to write our what they will share when groups come to their whiteboard. Additionally, they can carry a paper with them to help them engage in meaningful discussion as they learn from other groups.
Hands-on Activity Instructions
Note: Students can adjust several variables that will affect the functionality of the electromagnet crane.
Electromagnetic Forces Assessment
Sample Rubric: from STEM Teaching Tools here
Differentiation
If students are struggling to understand the concepts, or are not being safe with lab materials they can use this phet simulation and additional lab sheet posted on the phet.colorado.edu website. It could be done in partners.
Remediation
Extension/Enrichment
Additional Electromagnet investigation looking at number of coils and the strength of the electromagnet.