## Magnetism and the Magnetic Force

### J.P. HamiltonOrange County Schools

#### Description

Students investigate magnetism and magnetic force.

#### Objectives

Interprets data that has been collected, organized, and displayed in charts, tables, plots.

The student knows that as electrical charges oscillate, they create time-varying electric and magnetic fields that propagate away from the source as an electromagnetic wave.

The student describes how magnetic force and electrical force are two aspects of a single force.

The student knows that investigations are conducted to explore new phenomena, to check on previous results, to test how well a theory predicts, and to compare different theories.

#### Materials

Per group:
-1 ring stand
-1 clamp
-1 strong magnet
-2 screws of different size
-digital balance
-graph paper for each student
-meter stick

#### Preparations

A discussion of forces, magnetism, and the magnetic force may be necessary prior to this activity.
Gather lab materials. (Magnets may need to be purchased.)

#### Procedures

1. Divide students into groups of two or three.
2. Have groups set up a ring stand with a digital balance placed on the base (See Associated File).
3. Student will put a strong magnet on the balance and record its mass.
4. Students will place a large screw, head pointing downward, in a clamp attached to the ring stand; they will use the meter stick to measure 40 cm directly above the magnet and position the screw.
5. Ask students to read the balance and record the (apparent) mass of the magnet.
6. Instruct students to move the screw closer to the magnet in 5 cm intervals, recording the mass of the magnet at each interval.
7. Students will replace the screw with a smaller screw and repeat the experiment.

Analysis:

8. Students will create one graph recording both sets of data collected. Clearly indicate on the graph the size screw used for each set of data. Label the axes (distance vs. apparent mass) and title the graph.
9. Within a synoptic journal, or as a writing exercise, students will explain the findings of their experiment (the relationship of the proximity of the screw and the magnet to the mass readings of the magnet).
10. Assess the graph and writing exercise for student understanding.

#### Assessments

The graph and journal entry or writing exercise may be used to assess this activity formatively. The following ideas may be useful in developing an assessment:
-- accurate explanation indicating a thorough comprehension
--correct mechanics
--correct graph including labeled axes and title

The following questions may be used to assess student understanding:

1. Which of the following is true of the magnetic force?
a. It is dependent on the material used.
b. It is dependent on the mass of the screw.
c. It is dependent on the mass of the magnet.
d. All the above.

(Answer d: The magnetic force is dependent on all of these items.)

2. Which of the following would affect the magnetic force the most?
a. Time
b. Mass of screw and magnet
c. Distance between screw and magnet
d. Gravity

(Answer c: The distance affects the force the most.)

3. Magnetism is caused by:
a. Proton alignment
b. Electron placement
c. Neutron number
d. Atomic mass

(Answer b: Magnetism is caused by unpaired electrons within electron orbitals.)

FCAT Math (Extended Response):
Create one graph recording both sets of data collected. Clearly indicate on the graph the size screw used for each set of data. Label the axes (distance vs. apparent mass) and title the graph. Write an interpretation of the graphical representation of the data.

#### Extensions

Research the effects of magnetism on the human body. It is thought that there may be some physical benefit to using magnetism as a healing tool.

#### Attached Files

Ring stand and iron ring diagram     File Extension: pdf