Question 1204545
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Answers:<ol type="a"><li><font color=red>15 meters</font></li><li><font color=red>90 seconds</font></li><li><font color=red>1 meter</font></li></ol>Explanation for part (a)
The radius of the wheel is equal to the amplitude. 
The template {{{y = A*cos(B(x-C))+D}}} has |A| as the amplitude. 
In this case the amplitude is |-15| = 15. 



An alternative approach for part (a)
The highest and lowest points are when h(t) = 31 meters and h(t) = 1 meter respectively (recall that {{{-1 <= cos(x) <= 1}}}). 
This is a distance of 31-1 = 30 meters, which represents the diameter of the wheel. The radius is half that.



Explanation for part (b)
The period T is calculated with the formula {{{T = (2pi)/(B)}}}. 
In this case {{{B = pi/45}}}. 
Plug that value of B into the equation to get T = 90. The cosine curve repeats itself every 90 seconds.



Explanation for part (c)
Plug in t = 0 to get h(0) = 1. 
I'll leave the scratch work and steps for the student to do.
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