Department of Energy Argonne National Laboratory Office of Science NEWTON's Homepage NEWTON's Homepage
NEWTON, Ask A Scientist!
NEWTON Home Page NEWTON Teachers Visit Our Archives Ask A Question How To Ask A Question Question of the Week Our Expert Scientists Volunteer at NEWTON! Frequently Asked Questions Referencing NEWTON About NEWTON About Ask A Scientist Education At Argonne Music and Standing Waves
Name:  Sriram S.
Status: student
Age: 15
Location: N/A
Country: N/A
Date: 2000-2001


Question:
we say that a standing wave pattern is formed along the length of a FLUTE. we also say that energy is not transported to the left or right in a standing wave. are these two statements contradictory? if not, what do they actually mean that energy in standing wave is "standing" as we can hear the musical notes from a FLUTE.


Replies:
Sriram,

A flute vibrates when blown. Before anything has a chance to begin, nothing is vibrating. As the air from your mouth hits the "mouthpiece end" of the flute, some energy is transferred to the flute itself. This sends some vibration down the length of the flute. At the far end, there is nowhere for the energy to go, so it reflects back up toward the mouthpiece. In a very short time, amount of energy going down the flute (as a wave) is balanced by the amount coming back up (another wave). This balance has the effect of producing a standing wave. If there were no air molecules outside the flute, this energy would bounce back and forth almost forever.

Because the vibrating sides of the flute smash into air molecules, some energy gets transferred to the air around the flute. It is not in the direction of the flute's standing wave (up or down the length of the flute). The air near the flute is made to vibrate at the frequency of the flute itself. These air molecules then smash into neighboring air molecules, and you have a sound wave carrying energy to your ears.

Dr. Ken Mellendorf
Illinois Central College



Click here to return to the Physics Archives

NEWTON is an electronic community for Science, Math, and Computer Science K-12 Educators, sponsored and operated by Argonne National Laboratory's Educational Programs, Andrew Skipor, Ph.D., Head of Educational Programs.

For assistance with NEWTON contact a System Operator (help@newton.dep.anl.gov), or at Argonne's Educational Programs

NEWTON AND ASK A SCIENTIST
Educational Programs
Building 360
9700 S. Cass Ave.
Argonne, Illinois
60439-4845, USA
Update: June 2012
Weclome To Newton

Argonne National Laboratory