Question

Karl starts the engine on his small private airplane. The engine drives a propeller with a radius of 9 feet and its centerline 12.5 feet

above the ground. At idle, the propeller rotates at a constant speed of approximately 750 revolutions per minute. The height of one

propeller tip as a function of time is given by h = 12.5 + 9 sin(7501), where h is the height in feet and t is the time in minutes. Find h

when t= 3.5 minutes.

Answer 1

A. 21.1

Explanation:

Below is a picture that states that 21.1 is indeed the correct answer.

Answer 2

Answer: The height of one propeller tip is 3.68 feet when t= 3.5 minutes.

Explanation:

Given: The height of one propeller tip as a function of time is given by
`h = 12.5 + 9 sin(750t)`), where h is the height in feet and t is the time in minutes.

Put t = 3.5 , we get

`h=12.5 +9 \sin (750*3.5)\\\\=12.5+9\sin (2625)\\\\=12.5+9(-0.9802)\\\\=12.5-8.8218=3.6782\approx3.68`

Hence, The height of one propeller tip is 3.68 feet when t= 3.5 minutes.