Question

A simple model of the core of a tornado is a right circular cylinder that rotates about its axis. If a tornado has a core diameter of 160 feet and maximum wind speed of 150 mi/hr (or 220 ft/sec) at the perimeter of the core, approximate the number of revolutions the core makes each minute.

Question 8 options:

25.3 rev/min

24.3 rev/min

26.3 rev/min

23.3 rev/min

Answer 1

26.3 rev/min

Explanation:

The angular velocity (ω) is the linear velocity divided by the radius ( r= 80 feet)

ω = 220/80 = 2.75 rad/s

The angular velocity and the frequency are related by:

ω = 2π*f

2.75 = 6.28*f

f = 2.75/6.28

f = 0.438 rev/s * 60s/1min

f = 26.3 rev/min