Answer:
x = 25% percent decrease
Step-by-step explanation:
For this problem we will use percentage calculation and make proportion:
Initial value 56 points is worth 100%
Second value 56 - 42 = 14 points of decrease is worth x%
56 : 14 = 100 : x
When we multiply external and internal members we get:
56 · x = 14 · 100 => x = 1400/56 = 25%
x = 25% percent decrease
God with you!!!
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.
Because it is every hour there's 60min so that's and hour the the next 45 min are different