Mathematics and Society - OS X Lion Server

Angle measurements and scale drawingscan be used to determine the distance tothe moon or man-made earth satellites.For example, an observatory in Minneapolisobserves the satellite Echo at 10:30in the evening. It is 36° from the zenithin a southerly direction. (Zenith refersto the position in the sky directly abovethe observer's head.)At the same time astronomers in NewOrleans observe that Echo appears to be 30°from the zenith in a northerly direction.These two observations and a scaledrawing can be used to find the height ofEcho above the surface of the Earth. (Themethod described below works only forcities along the same north-south line.)To make the scale drawing:1. Draw a circle with radius 5 em torepresent the Earth.2. Mark the equator and draw linesegments to represent the parallelsof latitude for l5°N, 30 0 N, 45~N,60 0 N as shown in figure 1.. , , ,, ,......... \ //"'W'GO' t.I LATITUDE:/,"Jt2"'. '30 0 \3Go---•,~o \ ' MIt.lf.l>:APOUS