# Waves and Sound

Student Learning Objectives
Lessons / Lecture Notes
Important Equations
Example Problems
Pencasts
Applets and Animations
Videos

Student Learning Objectives

• To visualize wave motion and develop intuition about waves.
• To understand how waves travel through a medium.
• To understand the difference between transverse and longitudinal waves.
• To become familiar with the properties of sinusoidal waves, such as wavelength, wave speed, amplitdue, and frequency.
• To study the properties of common waves - waves on strings, sound waves, and light waves.
• To apply energy and power concepts to waves.
• To use the decibel scale for sound intensity.
• To understand the Doppler Effect.

Lessons / Lecture Notes

The Physics Classroom (conceptual)

PY105 Notes from Boston University (algebra-based):

HyperPhysics (calculus-based)

PHY2048 notes from Florida Atlantic University (calculus-based):

General Physics I notes from ETSU (calculus-based)

Important Equations

Example Problems

Problem 1
(a) The middle C string on a piano is under a tension of 944 N. The period and wavelength of a wave on this string are 3.82 ms and 1.26 m, respectively. Find the linear density of the string.

(b) A string of length 0.500 m is fixed at both ends. The string is plucked and a standing wave is set up that is vibrating at its fourth harmonic. The traveling waves that make up the standing waves have a speed of 140 m/s. What is the frequency of vibration? (Solutions)

Problem 2
Two submarines are underwater and approaching each other head-on. Sub A has a speed of 12.0 m/s and sub B has a speed of 8.00 m/s. Sub A sends out a 1550 Hz sonar wave that travels at a speed of 1522 m/s. (a) What is the frequency detected by sub B? (b) Part of the sonar wave is reflected from B and returns to A. What frequency does A detect for this reflected wave? (Solutions)

Pencasts

Waves and Sound
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