posted by Alex .
A toy plane of mass 0.624 kg is flown in a circle when attached to a string. The plane moves around the circle with a rotational speed of 8.09 rpm. The length of the string is 2.60 m.
What is the tangential velocity, v, of the plane?
Well, you certainly don't need to know the mass to compute that.
Since is revolves at 8.09 rpm, the plane travels
2*pi*R*8.09 = 132.2 meters, tangentially (around the circle) in 60 seconds.
Take the ratio of those two numbers and you will have the speed in meters per second.