Posted by Erin on Saturday, April 12, 2008 at 4:52pm.
The outstretched hands and arms of a figure skater preparing for a spin can be considered a slender rod pivoting about an axis through its center. When the skater's hands and arms are brought in and wrapped around his body to execute the spin, the hands and arms can be considered a thinwalled hollow cylinder. His hands and arms have a combined mass of 8.50kg. When outstretched, they span 1.80m; when wrapped, they form a cylinder of radius 25.0cm. The moment of inertia about the axis of rotation of the remainder of his body is constant and equal to 0.450 kg·m^2. If the skater's original angular speed is 0.450 rev/s, what is his final angular speed?

physics  drwls, Saturday, April 12, 2008 at 6:59pm
The total moment of inertia with arms outstretched is:
I1 = Ibody + Iarms = 0.450 + (1/12) m L^2 = 0.450 + (1/12)*8.5*(1.8)^2 = 2.75 kg m^2
The total moment of inertia with arms rapped aound the body is:
I2 = Ibody + Iarms = 0.450 + m R^2 =
0.45 + 0.53 = 0.98 kg m^2
Use the conservation of angular momentum equation
I1*w1 = I2*w2 to get the final anglualr speed w2. It should increrase by about a factor of 3.

physics  ozy, Sunday, March 22, 2009 at 8:31pm
drwls thanks so much. your solution is absolutely right haha =) i got a similar qns to that of Erin too. and managed to solve it thanks to u.

physics  Claudia, Wednesday, December 4, 2013 at 2:01am
1.10
Answer This Question
Related Questions
 Physics  The outstretched hands and arms of a figure skater preparing for a ...
 Physics  The Spinning Figure Skater. The outstretched hands and arms of a ...
 physics  a skater holds her arms outstretched as she spins at 140 rpm. What is ...
 Physics  A figure skater rotates about a vertical axis through her center with ...
 ice skater world problem  A skater spins with an angular speed of 12.4 rad/s ...
 physics  An ice skater has a moment of inertia of 2.3 kg * m^2 when his arms ...
 Physics  A figure skater is spinning with her arms out wide. Will she spin ...
 Physics  An ice skater spins with his arms outstretched. When he pulls his arms...
 Physics  A figure skater is spinning at a rate of 1.1 rev/s with her arms ...
 physics  A figure skater is spinning at a rate of 1.7 rev/s with her arms ...
More Related Questions