Posted by jade on .
A space station is shaped like a ring and rotates to simulate gravity. If the radius of the space station is 150 m, at what frequency must it rotate so that it simulates Earth's gravity? [Hint: The apparent weight of the astronauts must be the same as their weight on Earth.]
what do i do with the radius?

physics 
drwls,
Use the radius in the formula
g = V^2/R
g is the centripetal acceleration that you want to achieve (equal to that of Earth's gravity). V is the velocity of the outer perimeter of the ring.
Once you have V, the rotation frequency is
f = 1/T = V/(2 pi R)
= [1/(2 pi)] * sqrt(g/R)