Finding revolutions per minute

chenying

1. The problem statement, all variables and given/known data

An astronaut is rotated in a centrifuge of radius 4.0 m.

2. Relevant equations

v = omega * radius

a = v^2/radius


3. The attempt at a solution

Ok, so I first found the omega for this acceleration, which came out to be

omega = 3.56179 s^-1

then I decided that since the it is revolutions per minute, I multiplied the vaule of omega by 60 seconds, and divided the value by the circumference of the circle.

(2*pi*4)/210.107 = .119619

So this answer is completely wrong because it does not make any sense whatsoever

Kalvarin

You need to know more data to work out the rpm, knowing just the radius of the centrifuge is not enough.

chenying

This was all that was given to me.

Anden

Omega = 2pi / Time, then you can get the time of one revolution

Kalvarin

Well rpm for a gven radius can infinetly many values. How did you work out the value of omega?

chenying

I used a = V^2/r since i have acceleration and r

Once I got the value of V, i substitute it into v = omega * radius and solved for omega.

Anden

You have forgotten to state the value of a in the question above.

Kalvarin

Oh ok, well then just use your value of omega in the formula anden gave you. That is the time for 1 revolution.

chenying

Sorry, the acceleration is 5g