breaking strenght of a cord is 44lbs. what's the max freq of rev of a 8lb wt rotating in a hor cir of rad 10ft

Question

breaking strenght of a cord is 44lbs. what's the max freq of revolution of a 8lb weight rotating in a horizontal circle of radius of 9ft.

Answer 1

To move a mass in a circle, a centripetal force must be applied. That force is

F = m r ω^2

This force must be supplied by the cord, which breaks at 44 lbs. Therefore

44 lbs = m ( 10 ft ) ω^2

The twist is that you now need the mass in slugs ( a pound is a slug-foot per second squared). The conversion is 1 pound = 0.0310809502 slugs.

44 lbs = ( 8 lbs ) ( 0.0310809502 slugs / lb ) ( 10 ft ) ω^2

Solve for the angular velocity ω.