Posted by **Amber** on Wednesday, April 25, 2012 at 12:18am.

Two ice skaters hold hands and rotate, making one revolution in 7.6 s. Their masses are 15 kg and 50 kg, and they are separated by 4.6 m.

Find the angular momentum of the system about their center of mass.

Answer in units of J · s

Find the total kinetic energy of the system.

Answer in units of J

- Physics. PLEASE HELP!! -
**Damon**, Wednesday, April 25, 2012 at 2:10am
These are pretty crazy measurements for human ice skaters but anyway

w = 2 pi/7.6 = .827 radians/second

find center of mass at x from big one

x(50)=(4.6-x)(15)

50 x = 69 - 15 x

65 x = 69

x = 1.06 m from big one and 3.54 from little one

I = 50(1.06)^2 + 15(3.54)^2

= 244 kg m^2

L = ang momentum = I w

= 244 (.827)

= 202 kg m^2/s

- Physics. PLEASE HELP!! -
**Cesar**, Wednesday, April 25, 2012 at 12:20pm
for KE

since you already have all the numbers...

KE1 + KE2 = (.5*I1*W1^2) + (.5*I2*W2^2)

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