MnSTEP Teaching Activity Collection > MnSTEP Activities > Investigating The Magnetic Force Field: Calculating the magnetic pull of a magnet by varying distances.

# Investigating The Magnetic Force Field: Calculating the magnetic pull of a magnet by varying distances.

#### Summary

In this classroom activity, the students will investigate the magnetic pull of a bar magnet at varying distances with the use of paper clips. Students will hypothesize, conduct the experiment, collect the data, and draw conclusions that support their data. Each student will record the experiment and their findings in their science journals. As a class, students will compare each groups data and their interpretation of the results.

## Learning Goals

1. Students will be able to understand that the magnetic
force is greatest when the object is the closest to the
magnet.
2. Students will be able to understand that the magnetic
force decreases as the distance increases between the
object and the magnet.
3. Students will be able to understand that the magnetic
power passes through the objects it attracts.
Key Concepts:
1. Magnets have an invisible force that pulls things
towards them or pushes them away.
This force cannot be seen, but the way it acts can be
seen.
2. The bar magnet has a magnetic pole at each end. The
force of a magnet is strongest at the poles.

Vocabulary Words:
1. Magnetic force field
2. Attract

## Context for Use

This lesson is best suited for the classroom and will require two science periods to complete. On the first day, the actual experiment will take about 45 minutes. On the second day, the sharing of results will take at least 20-30 minutes. If the students will not have much exposure to formulating hypotheses prior to this activity, I recommend completing this part of the lesson as a whole group. As for the experiment, the students will be in groups of three. The students will be placed in heterogeneous groups so that they can help one another. The students will need to have prior knowledge about rulers, and know how to accurately read and measure with them (centimeter side).

Subject: Physics:Electricity & Magnetism
Resource Type: Activities:Classroom Activity

## Description and Teaching Materials

Materials:

-Bar magnet
-20+ large metal paper clips
-Ruler
-Science journal
-Pencil to record the experiment, data, and results.

Procedure:

1. Introduce the lesson by asking the students to consider
how far magnetic force reaches, and introduce the
vocabulary, "force field." Model the procedure for the
lesson. State that we will conduct an experiment to
find out how the distance between a magnet and a pile
of paper clips affect the magnetic force field of a
magnet.
2. As a whole group, ask the students to
predict what will be the possible outcomes
of the experiment and write these
hypotheses in their science journals.
3. Students will draw a table/chart in their science
journals to record their data on.
On one side of this T-chart will be the distance
(0cm., 2cm., 4cm., 6cm., 8cm., 10cm., 12cm.) and
on the other side of the T-chart will be the number of
paper clips. This chart can be horizontally or
vertically drawn.
4. Each group will the tape the ruler on a desk/table.
They will lay the paper clips next to the 0cm. mark
on the ruler. Position one end of the bar magnet next
to the 12cm. mark on the ruler.
5. Watch and see if the paper clips move toward the
magnet. Record the number of paper clips that are
are pulled toward the magnet on the table/chart.
6. Move the end of the bar magnet from the 12cm. mark to
the 10cm. mark on the ruler.
7. Watch and see if the paper clips move toward the
magnet. Record the number of paper clips that are
pulled toward the magnet on the table/chart.
8. Have the students continue to move the end of the bar
magnet next to the following places on the ruler:
8cm., 6cm., 4cm., 2cm., and 0cm. After each movement
of the bar magnet, have the students record the
number of paper clips that are pulled toward
the magnet in their science journals.
9. After the experiment, students will discuss in their
groups their interpretation of the data.
10. Each group will share their findings with the whole
class. As a whole group, the students will decide
which hypothesis supports their data. Students will
record this hypothesis in their science journal.

## Teaching Notes and Tips

I recommend that the students are grouped in teams with varied mathematical abilities. Then students can help each other with the measuring component of this task. In addition, model how to set this experiment up before letting the groups conduct this experiment independently. This will alleviate any confusion for the students. Since I have not done this type of inquiry-based experiment with my students before, this will probably take a little longer to implement. Allow students to ask clarifications questions as needed. Give the students as much guidance as needed. In addition, an alternative to the science journal can be an already created T-chart for the students to record their data on.

## Assessment

*The teacher can make anecdotal records that reflect how each group gathers and interprets data.
*The teacher can make anecdotal records of what the student responses are in whole group discussion.
group discussion.
*The teacher can evaluate the students thinking processes from the science journals. Journals need to state the
hypotheses, what the experiment entails, the collected data,
and the conclusion that supports this data. Use a rubric for evaluating the science journals according to this
criteria (hypothesis, details of experiment, data, and
conclusion).

## Standards

The physical science standard that this lesson reflects is forces of nature. This standard focuses on the student understanding that forces can act at a distance.