Investigating Sound Waves
Initial Publication Date: August 25, 2009
Summary
In this Physical Science experiment, students investigate how sound travels through different mediums, including solids, liquids, and gases. This particular experiment deals with solids by using a wire hanger and two pieces of cotton string. Students will work individually and keep notes in their journals of their observations.
CollapseLearning Goals
Students will be able to understand that sound is a form of energy that travels in waves referred to as compressional waves. Students will learn that sound waves travel in a specific direction until something gets in their way and reflects it. Students will investigate different sounds by using different objects in the room.
Context for Use
This experiment can be carried out in the classroom as well as the lab, and may be performed with K-8 graders. The time allowed for this activity may vary because students should have a wide variety of objects they will be listening to as well as comparing and contrasting different types of strings and lengths of string. The concepts of sound traveling through energy waves should be discussed prior to this experiment. This activity would easily be adapted for use in other settings as long as there was a variety of objects around the room.
Description and Teaching Materials
Materials needed:
1 wire hanger per student
2 cotton strings tied onto neck of hanger so as to form a "V" when hanger is dangling from fingers.
wrap ends of string around pointer fingers so that hanger is dangling below chin, or hanging near chest. Allow students to walk around room and carefully letting hanger "bang" into objects in room.
Students should observe the sound before and after placing hanger strings into ears. They should make observations in journal. Remind students to shorten their strings and make observations. If time allows, have students change the type of string used and make observations in journals. Have students observe tones, pitches, and other things that produce a broad range of frequencies. Allow students to tie string on different objects and to observe sound differences.
1 wire hanger per student
2 cotton strings tied onto neck of hanger so as to form a "V" when hanger is dangling from fingers.
wrap ends of string around pointer fingers so that hanger is dangling below chin, or hanging near chest. Allow students to walk around room and carefully letting hanger "bang" into objects in room.
Students should observe the sound before and after placing hanger strings into ears. They should make observations in journal. Remind students to shorten their strings and make observations. If time allows, have students change the type of string used and make observations in journals. Have students observe tones, pitches, and other things that produce a broad range of frequencies. Allow students to tie string on different objects and to observe sound differences.
Teaching Notes and Tips
It is best to come to class prepared, so I have a box of hangers with strings already attached. I have a separate box of other items with strings attached, and some hangers have different types of string attached (fishing line, small wire)
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Assessment
Students will be informally assessed by discussing their observations as they roam the room. Using journals, students will be assessed by reflecting, recording, and organizing their thoughts and observations.
Standards
3.2.3.1.1 Physical science: Energy. Energy appears in different forms including sound and light. The student will be able to explain the relationship between the pitch of a sound, the rate of vibration of the source, and factors that affect pitch. Students can change the length of the string to observe differences in sound, as well as changing the types of string being used.