Space stations and artificial gravity
Astronauts and jet pilots are trained in centrifuges where they are spun round at high speed to
simulate gravity and to test the "g force" that they can withstand.
Thinking about g forces you can
use the rotation of a space station to create the sensation of gravity at the rim. The "floor" would
be the outer edge of the space station and the rotation rate to give an acceleration equal to Earth's
gravity will vary depending on the size of the station but can be worked out using the equation for
centripetal acceleration: a = g = v2/r = 9.8 ms-2
Example problems
1. A space station has a radius of 100 m and is rotated with an angular velocity of 0.3 radians per second.
(i) which side of a "room" at the rim is the floor
(ii) what is the artificial gravity produced at the rim
(i) the floor is the outer rim of the space station
(ii) a = g = w2r = 0.32x100 = 9 ms-2
2. Calculate the rate of rotation for a space station of radius 65 m so that astronauts at the outer edge experience artificial gravity equal to 9.8 ms-2.
Using a = g = v2/r we have a = g = 9.8 = v2/65 and so v = 25.2 ms-1.
But T = 2pr/v and so T = 16.18 s
giving the rotation rate (1/T) as 0.062 Hz.
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