HELP ME PLEASE
Windmills are used to generate electricity. Suppose a particular windmill has a blade that is 140 ft long from the center of its mounting.
When the blade makes one complete rotation, how far (in ft) does the tip of the blade travel?
What is the surface area (in acres) that the rotating blades cover?

Respuesta :

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=2Ï€r

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