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A ferris wheel is 24m in diameter Nd boardered from a platform that is 1m above ground
and people entering th platform at height of 1m. The wheel completes one revolution in 10mins.
For how long is the wheel above 20m height in one cycle
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The radius of the wheel is 24/2 = 12 m.
The center of the wheel is at the height 1 + 12 = 13 m above the ground.
If "a" is the angle of the radius with the horizontal, then the set of values "a"
that are above 20 m over ground is sin(a) >= .
So, "a" is between = 35.7 degrees and 180 - 35.7 = 144.3 degrees.
This arc between 35.7 degrees and 144.3 degrees is about 144.3 - 35.7 degrees = 108 degrees (rounded).
Thus the time for the passenger to be higher than 20 m over the ground is
= = 10*0.3 = 3 minutes, approximately.
ANSWER. 3 minutes, approximately.
Solved.