the circular blade on a saw has a diameter of 7.5 inches and rotates at 2400 revolutions per minute. A) find the angular speed in radians per sec B) Find the linear speed of the saw teeth ( in feet per sec) as the contact the wood being cut. Formulas--> Linear speed= arc length/time= s/t Angular speed= central angle/time arc length s= radius r * central angle(in radians)
the answer in the book is 80pi rad per sec for a and 25pi ft per sec for b but i dont know how to get to that...
There are 2pi for every revolution
so we multipy 2pi * 2400 this is angular speed in minutes, we want is in sec ; so divide by 60 2pi * 2400/60 =80pi
linear speed = radius time angular speed
radius= 7.5/2=3.75 inches=.3125 feet
b)linear speed = radius x angular speed .3125 x 80pi=25 pi
ur wrong you wouldn't divide by 60 you would multiply thus getting the wrong answer
for the min to sec thing
but it matches your answer
the angular speed is wrong you would multiply 60 to convert min to sec
If I run 60 miles per minutes, how many miles do I run in a second?
1 mi per sec?
yeah, did you divide or multiply by 60?
divide
2400 1 min -----*------ = 240/6 rps 1 min 60 sec
okay i got what your saying thanks :) and im sorry that i said you were wrong
no problem, glad to help
Join our real-time social learning platform and learn together with your friends!