When the blade makes one complete rotation, how far (in ft) does the tip of the blade travel?
Because the blade is 140, we that means the radius is 140. So we need to find the circumference of the circle.
C=2πr
C = (2)(3.14)(140)
C = 879.2 ft
The blade travels 879.2 feet
What is the surface area (in acres) that the rotating blades cover?
A = πr²
A = (3.14)(140)²
A = (3.14)(19600)
A = 61544 ft²
An acre = 43,560 feet
61544 / 43560 = 1.41285583
The surface area the rotating blades covers is 1.41 acres