Standing Waves Lab
Name: Kyle Collins
Lab Partner: Hunter McCabe
Date: 4 May 2015
Purpose: To determine velocity of standing waves with various amounts of nodes.
Theory: Standing waves are defined as "a vibration of a system in which some particular points remain fixed while others between them vibrate with the maximum amplitude." The fixed points are called nodes and the points with maximum amplitude are antinodes. Waves vibrating at different frequencies produce different harmonics and overtones.
Lab Partner: Hunter McCabe
Date: 4 May 2015
Purpose: To determine velocity of standing waves with various amounts of nodes.
Theory: Standing waves are defined as "a vibration of a system in which some particular points remain fixed while others between them vibrate with the maximum amplitude." The fixed points are called nodes and the points with maximum amplitude are antinodes. Waves vibrating at different frequencies produce different harmonics and overtones.
Velocity can be found in a standing wave by one of two waves...
Experimental Technique: A stretchy cord was attached to the string vibrator and stretched over a pulley; a mass hanger was hung over the free end of the string. The mass on the hangar was varied to change the number of loops on the string. Once a good wave was established, a mark was placed at the end node on top of the pulley. The string, once all runs were completed, was removed and cut to the lengths marked, where the string was then massed. Tension and wavelength were then calculated, and used to compare velocities two different ways.
Data and Analysis: The tension on the string was varied to produce waves ranging from 13 loops to 4 loops. This was calculated by taking the mass of the hanging weight and multiplying it by 9.8 m/s^2 (acceleration due to gravity). This produced the data in column E of the table. To find mu, the following equation was used:
The calculation for wavelength is as follows:
With these calculations done, the two calculations for velocity can be done.
And lastly, these two velocities are compared with a percent difference equation.
Conclusion: Given the very low percent differences, it can be assumed (as was expected) that no matter how it is measured, velocity in a standing wave is always the same.
References:
Standing Wave Definition. (n.d.). Retrieved May 13, 2015, from https://www.google.com/search?q=standing wave definition&ie=utf-8&oe=utf-8
Giancoli, D. (2009). Physics for Scientists and Engineers (4th ed.). Chapter 15 - Wave Motion. Upper Saddle River, N.J.: Pearson Prentice Hall.
Lahs Physics. "Standing Waves Lab". Retrieved May 13, 2015 from www.lahsphysics.weebly.com
References:
Standing Wave Definition. (n.d.). Retrieved May 13, 2015, from https://www.google.com/search?q=standing wave definition&ie=utf-8&oe=utf-8
Giancoli, D. (2009). Physics for Scientists and Engineers (4th ed.). Chapter 15 - Wave Motion. Upper Saddle River, N.J.: Pearson Prentice Hall.
Lahs Physics. "Standing Waves Lab". Retrieved May 13, 2015 from www.lahsphysics.weebly.com