Sound Waves Legacy Problem #4 Guided Solution
Problem*
Mama G used to be the leader of South's Pep Club. As she started in on a round of Wash Them Down the River, her voice would ring out at an attention-drawing 855 Hz. Assuming a speed of sound in the Titan Dome of 355 m/s, determine the wavelength of the sound waves produced by Mama G.
Audio Guided Solution
In this question, I'm given the frequency of sound waves, 855 Hz, and the speed at which the sound waves travel through air, 355 meters per second, and I'm asked to calculate the wavelength of the sound waves. I'll need to use the wave equation, v equals f times lambda, where v is the speed and f is the frequency in lambda, that's the wavelength. Rearranging the equation to solve for wavelength, I would have lambda, or wavelength, equal v divided by f. I can take my v value, 355 meters per second, and divide it by my f value of 855 Hz. That will give me a wavelength. When I do, I get 0.4152 meters. I can round that to three significant digits. I could even express it in centimeters. It's 41.5 centimeters.
Solution
0.415 m or 41.5 cm
Habbits of an Effective Problem Solver
- Read the problem carefully and develop a mental picture of the physical situation. If necessary, sketch a simple diagram of the physical situation to help you visualize it.
- Identify the known and unknown quantities and record in an organized manner, often times they can be recorded on the diagram itself. Equate given values to the symbols used to represent the corresponding quantity (e.g., \(\descriptive{v}{v,velocity} = 345\unit{\meter\per\second}\), \(\descriptive{λ}{λ,wavelength} = 1.28 \unit{m}\), \(\descriptive{f}{f,frequency} = \colorbox{gray}{Unknown}\)).
- Use physics formulas and conceptual reasoning to plot a strategy for solving for the unknown quantity.
- Identify the appropriate formula(s) to use.
- Perform substitutions and algebraic manipulations in order to solve for the unknown quantity.
Read About It!
Get more information on the topic of Sound Waves at The Physics Classroom Tutorial.