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The paddle wheel of a boat measures 16 feet in diameter and is revolving at a rate of

20 revolutions per minute. The maximum depth of the paddle wheel under water is 1
foot. Suppose a point is located at the lowest point of the wheel at t=0. Write an
equation for the height of the initial point after t seconds.
A h= -8 cos 3t + 7
B h= 8 cos (Ft) +7
C h=8 cos (Ft) + 7
D h= 8 cos 3t +7

1 Answer

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Final answer:

The correct equation for the height of the initial point after t seconds is h = 8 cos (40πt) + 7, considering the paddle wheel's radius, the rate of revolution, and the maximum depth underwater.

Step-by-step explanation:

The paddle wheel of a boat measures 16 feet in diameter and is revolving at a rate of 20 revolutions per minute. The maximum depth of the paddle wheel under water is 1 foot. In order to determine the equation for the height of the initial point after t seconds, we'll have to consider the motion of the paddle wheel which can be modeled using sinusoidal functions, specifically the cosine function for a vertical circular motion.

Given:

  • The diameter of the paddle wheel is 16 feet, so the radius (r) is half of that, i.e., 8 feet.
  • The wheel makes 20 revolutions per minute, hence it completes one revolution in 3 seconds (t).
  • The maximum depth under water is 1 foot which means the wheel dips 8 - 1 = 7 feet below the water level at the lowest point.

The equation for the height h of the point after t seconds in terms of cosine is:

h = 8 cos (40πt) + 7

where 40π is the angular velocity in radians per second (20 revolutions x 2π radians/revolution x 1 minute/60 seconds).

User Joseph Jaquinta
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