Posted by George on Thursday, September 2, 2010 at 12:52pm.
Astronauts use a centrifuge to simulate the acceleration of a rocket launch. The centrifuge takes 30.0 s to speed up from rest to its top speed of 1 rotation every 1.10 s. the astronaut is strapped into a seat 7.40 m from the axis.
A) What is the astronaut's tangential acceleration during the first 30.0 s?
B) How many g's of acceleration does the astronaut experience when the device is rotating at top speed? Each 9.80 m/s^2 of acceleration is 1 g.

Physics (Circular Motion!!)  drwls, Thursday, September 2, 2010 at 2:30pm
A) Top angular speed is
wmax = 2 pi radians/1.1 s = 5.71 rad/s
Angular acceleration during first 30 s: alpha = 5.71/30 = 0.1904 rad/s^2
Tangential acceleration = R*alpha = 0.952 m/s^2
B) centripetal acceleration at top speed = R*wmax^2 = 163 m/s^2 = 16.6 g's 
Physics (Circular Motion!!)  George, Thursday, September 2, 2010 at 2:38pm
Thank you for trying to help, but that is what i've been getting and my homework website tells me it is wrong. But now its two on one so i'm starting to think that the website is wrong

Physics (Circular Motion!!)  Colton, Sunday, October 17, 2010 at 6:14pm
You have to use the first kinematics equation Vfinal = Vinitial + at. The initial velocity is 0, so Vfinal = at. Find the final velocity (where it reaches its top speed) by 2piR (where R is the radius) / time of 1 revolution. Then divide the final velocity by the total time it takes to reach that speed, and that gives you the acceleration for part A.

Physics (Circular Motion!!)  Eldon, Sunday, March 6, 2016 at 7:07pm
R=7.4m in this question by the way. Thought it would be useful to clarify that.