Pilots and astronauts who experience high levels of acceleration may experience
ID: 1524636 • Letter: P
Question
Pilots and astronauts who experience high levels of acceleration may experience ginduced loss of consciousness (abbreviated G-LOC). Some trained individuals, wearing g-suits and practicing the “straining maneuver”, can sustain 9g accelerations without losing consciousness. For testing, NASA has a 58 ft diameter centrifuge capable of producing 20g, although humans are only allowed to experience 12.5g. a) What speed of rotation in rpm is necessary to reach 9g? b) If you want the centrifuge to reach this rotational speed from rest in 2 minutes, what constant angular acceleration is necessary?
Explanation / Answer
R = 58/2 ft = 8.84 m
and a = w^2 R
(A) 9g = w^2 R
9 x 9.81 = w^2 x 8.84
w = 3.16 rad/s = 3.16 x (1/2pi) round / (1/60)min
w = 30.18 rpm
(b) wf = wi + alpha t
3.16 = 0 + alpha (2 x 60 sec)
alpha = 0.0263 rad/s^2 Or 15.09 rev / min^2