A group of N = 773 astronauts, with average mass m = 78.1 kg, work on a space st
ID: 1909035 • Letter: A
Question
A group of N = 773 astronauts, with average mass m = 78.1 kg, work on a space station. The station is in the form of an approximately solid disk (M = 90900 kg, R = 772 m). (You may treat the people as point particles.) Suppose the space station spins at fo = 8.05 revolutions per minute when all the astronauts are in their quarters on the very edge of the space station. Find ffinal, the frequency of revolution if the entire population moves into an auditorium in the very center of the space station. Assume there are no external torques on the disk. revolutions/minuteExplanation / Answer
Total moment of inertia when the astronauts are in their quarters : 0.5 * 90900 * 772 ^2 + 773 * 78.1 * 772^2 = 6.3067 x 10^10 kg m^2 Final Moment of INertia = 0.5 * 90900 * 772 ^2 = 2.70 x 10^10 kg m^2 w1 = 8.05 rev /min So, by conservation of angular momentum...I1 * w1 = I2 * w2.....we get... w2 = 18.74 rev / min