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ERIC Number: EJ891975
Record Type: Journal
Publication Date: 2007-Feb
Pages: 4
Abstractor: As Provided
Reference Count: 10
ISSN: ISSN-0031-921X
An Oscillating System with Sliding Friction
Kamela, Martin
Physics Teacher, v45 n2 p110-113 Feb 2007
Both harmonic oscillations and friction are the types of concepts in freshman physics that are readily applicable to the "real world" and as such, most students find these ideas interesting. Damped oscillations are usually presented with resistance proportional to velocity, which has the advantage of a relatively straightforward mathematical solution. This type of resistance occurs for very slow moving bodies in fluid, although a more common resistive force in fluid is proportional to velocity squared. Thus, mechanical oscillations with damping proportional to velocity may be more useful in the freshman course as an analogy for the future study of LRC circuits. Whereas an oscillator with damping proportional to velocity has an exponential decay in amplitude, a system with sliding friction results in amplitude that decays in a linear manner. In this paper I present a demonstration of an oscillator with sliding friction that exhibits very good agreement with a linear fall off in amplitude. The demonstration also confirms that sliding friction is proportional to the magnitude of the normal force.
American Association of Physics Teachers. One Physics Ellipse, College Park, MD 20740. Tel: 301-209-3300; Fax: 301-209-0845; e-mail:; Web site:
Publication Type: Journal Articles; Reports - Descriptive
Education Level: Higher Education
Audience: N/A
Language: English
Sponsor: N/A
Authoring Institution: N/A