Solving Rotational Speed Homework with Radius of 40cm

[zombie4000]

Homework Statement

Tire with a radius of 40cm spinning at 2500 rev/min. What is the rotational speed?

Homework Equations

w=v/r
w=2500revmin/40cm
w=62.5 rad/sec

Does that sound right? I am confused

 

[xxChrisxx]

Er... rev/min is a rotational speed.

Im not too sure what you are trying to work out.

 

[zombie4000]

Okay. Thats the exact problem I have on my sheet. I asked a few others and they said that the rev/sec is the rotational speed.

 

[xxChrisxx]

Look at your formula, and look at the units involved.

That will find a linear velocity at the outer edge of that ball, not rotational.

 

[zombie4000]

Thanks for the help!