In: Physics
A 45 kg figure skater is spinning on the toes of her skates at 0.50 rev/s . Her arms are outstretched as far as they will go. In this orientation, the skater can be modeled as a cylindrical torso (40 kg , 20 cm average diameter, 160 cm tall) plus two rod-like arms (2.5 kg each, 62 cm long) attached to the outside of the torso. The skater then raises her arms straight above her head, where she appears to be a 45 kg, 20-cm-diameter, 200-cm-tall cylinder. Part A What is her new rotation frequency, in revolutions per second? Express your answer to two significant figures and include the appropriate units.
What is her new rotation frequency, in revolutions per second?
In order to find the new angular velocity of the skater we have to use the conservation of angular momentum.
The angular momentum is given by, moment of inertia × angular velocity.