GEARS
Example 1.1
Two connected gears are rotating. The smaller gear has a radius of 0.4 m and
the larger gear's radius is 0.7 m. What is the angle through which the larger
gear has rotated when the smaller gear has made one complete rotation2
Answers
Step-by-step explanation:
Two gears are connected and are rotating simultaneously. The smaller gear has a radius of 3 inches, and the larger gear has a radius of 7 inches.
two circles touching at one point. Larger circle has radius of 7 inches. Smaller circle has radius of 3 inches.
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Larger circumference: 2pi*r = 14pi inches
Smaller circumference: 2pi*r = 6pi inches
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Part 1: What is the angle measure, in degrees and rounded to the nearest tenth, through which the larger gear has rotated when the smaller gear has made one complete rotation?
Ans: (6pi/14pi)(360) = (3/7)360 = 0.4286(360) = 154.29 degrees
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Part 2: How many rotations will the smaller gear make during one complete rotation of the larger gear?
Ans: # of rotations = 14pi/6pi = 7/3 = 2 1/3 rotations
Let C4 = 2pi(.4)
Let C7 = 2pi(.7)
Let F = Fraction of rotation
Let Angle = F * 360º
F = C4 / C7
= 2pi(.4) / 2pi(.7)
= 4 / 7
Angle = 4/7 * 360º
Angle = 205.7º