Eratosthenes Experiment Report

From: <dmacdonald_at_richfordk12.net>
Date: Fri, 27 Mar 2009 13:16:55 -0700 (PDT)
Experiment Report for the Eratosthenes Project on http://youth.net/

School Name:     Richford Jr-Sr High School (2)
School Location: Richford, Vermont, USA

Email Address:   dmacdonald_at_richfordk12.net
Experimenter:    Doug Mac Donald

Latitude         44.9945 N
Longitude:       72.6705 W
Distance to Equator: 5000.3738

Measured shadow angle in degrees: 45.047
Calculated Earth circumference:   39961

Comments:
For our location, we used 5 GPS units among 17 students and took the mean of the latitude and longitude values.  All students took two measurements of a meter stick's shadow at 12:21 PM EST (solar noon was 11:58 AM) on March 20.  They took the mean of the shadow lengths and used an inverse trig equation to calculate a shadow angle.  We took the mean of all 17 shadow angles and used that as the class shadow angle.  Using 111.133 km per latitude degree, we calculated our distance to the equator.  Then we used a proportion to calculate C.
Received on Fri Mar 27 2009 - 13:17:07 PDT

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