A circular power saw has an 8-1/2

inch diameter blade that rotates at 4400 revolutions per minute.

a)Find the angular speed of the saw blade in radians per minute.

b)Find the linear speed in feet per minute of one of the 24 cutting teeth as they contact the wood being cut.

I'd appreciate any help on this problem. I have 5 more like it, so I really just want to know how to go about it so I can do the rest. Thanks!

1 answer

a) one rotation = 2π radians
so 4400 rpm = 2π(4400) radians/min
= 8800π rad/min
= appr 27646 rad/min

b) one rotation = 2π(8.5) inches
= 17π inches
so 4400 rotations would be 17π(4400) inches
= 74800π

so the linear speed of a tooth = 74800π inches/min