Linear speed and rotational quantity

[baylorbelle]

What linear speed must a 6.0×10−2 hula hoop have if its total kinetic energy is to be 0.15 J ? Assume the hoop rolls on the ground without slipping.


So, i know that the formula for linear momentum is p=mv. however, the hoop is circular, meaning it has to have a rotational velocity (omega). I can't seem to figure out how the Joules play into any equation that helps link linear and rotational speeds. Anyone know of any formulas I can use for this problem?

 

[Doc Al]

If something is both translating and rotating, how do you determine its total kinetic energy?

What does "rolling without slipping" tell you about how translational speed relates to rotational speed?

 

[baylorbelle]

if something is rolling without slipping, it has rotational speed but not translational speed?

 

[Doc Al]

if something is rolling without slipping, it has rotational speed but not translational speed?

No, that would be an example of pure rotation. (And complete slipping!)

Read this: http://hyperphysics.phy-astr.gsu.edu/Hbase/rotwe.html#rke"