Area of a square = side^2
area = 6.25^2 =
<span>
<span>
<span>
39.0625
</span>
</span>
</span>
square feet
= 39.06 (rounded)
Answer:
7 feet is the length of the blade of the windmill.
Step-by-step explanation:
We have the equation
h = 7 sin(pi/21t) + 28 ------ eq1
At time 't' = 0, the end of the blade is pointing to the right parallel to the ground meaning it is at the same height as the other end. (Ф = 0°)
So, by calculating the maximum height of this end at Ф = 90°. we can calculate the length of the blade.
Now, we know that a general model equation of a circular simple harmonic motion is represented as : y = A sinωt + k ----- eq2
Where A is the amplitude that is, maximum displacement from mean to maximum position.
ω is the angular frequency.
Comparing eq1 and eq2:
A = 7
so the difference in blades end height at Ф = 0° and Ф = 90° is 7 feet.
Hence, the length of the blade is 7 feet.
The product is a bit less than the estimate. In fact, 7.69 is less than 8, and if you start with an equality, i.e.
you can multiply both sides by a positive number, and the inequality will still hold:
Answer:
Chris will take 0.75 seconds to return to his starting height of 10 feet.
Step-by-step explanation:
Let the height of Chris be represented by 
, where 
is the height in feet and 
, the time in seconds. First, we equalize the formula to a height of 10 feet and simplify the resulting expression, that is:
Then, we simplify the expression by algebraic means:
Roots of the polynomial are, respectively:
First root represents the initial height of Chris, whereas the second one represents the instant when Christ returns to the same height above the surface of the water. Hence, Chris will take 0.75 seconds to return to his starting height of 10 feet.
