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motion: TOC for Knowledge Concepts, Exercises, and Solutions

How much angle does the Moon subtend, as seen from Earth's surface?

(a) Look at a calendar or almanac to determine when the Moon will next be full.  
On that evening, find the Moon in the sky and hold a round object at arm's length 
between your eye and the Moon.  What size object most exactly blocks out the Moon, 
without being larger or smaller?  Objects you may wish to try might include a pie 
plate, a tennis ball, a golf ball, a coin, or a peppercorn.

(b) Compute the approximate angle the Moon subtends using the diameter of the 
object you used and the distance between your eye and your outstretched hand.