<PRE><B>Question 494860</B>
   1)The rotor blades of an helicopter are 16ft long and are rotaing at 120rmp.
  a)Find the angular speed of the rotor.
120 rev/min = 120*2*pi radians/min
= 240pi rad/min
------------
  b)find the linear speed of a point on the tip of a blade
The circumference = 16*2*pi feet
Tip speed = 16*2*pi*120 ft/min
= 3840pi ft/min
----------------
That helicopter is not likely to fly at those blade speeds, way too slow.
----------------
      2)Find the perimeter of a regular hexagon that is inscribed in a circle of radius 8m.
The central angles are 60 degs, making 6 equilateral triangles with sides of 8 m.
Perimeter = 6*8 = 48 m
</PRE>