The toy rocket hits the ground when h(t) = 0.
So, h(t) = 0 = -9t^2 + 81.
Solving the equation,
-9t^2 = -81
Dividing by -9
t^2 = 9
Taking the square root.
t = 3
The answer is 3 seconds.
First, get the difference between the price level changes.

Then, divide it by the initial price level, which is 109.

Multiply by 100 to get its percent.

Thefore, the inflation rate during the year is 3.67 percent.
Answer is 4/7
You divide the length of C'D' over the length of CD
C'D'/CD = 8/14 = 4/7
The scale factor is smaller than 1, so C'D' is shorter than CD
1. Area of a circle is pi x R^2
Area = 3.14 x 18^2
Area = 3.14 x 324= 1017.36 sq. In.
The blade covers 122 out of 360 degrees.
1017.36 x 122/360 = 345 square inches.
2.
Like above.
Area =3.14 x 75^2 = 17,662.5 square feet
17662.5 x 80/360 = 3,925 square feet.