A proposed space station consists of a circular tube that will rotate about its center (like a tubular bicycle tire). The circle formed by the tube has a diameter of 1.1 km. What must be the rotation speed (revolutions per day) in an effect nearly equal to gravity at the surface of the Earth (say, .90 g) is to be felt

1736rev/day

Explanation:

v = Velocity

d = Diameter = 1.1 km

r = Radius = 1.1km/2 =0.55 km = 0.55 × 10^3 m

g = Acceleration due to gravity = 9.81 m/s²

g = 0.9 g

Now use the centripetal force equation

F = mg

But to balance the gravitational force

F = mv²/r plug in this for F

Then we have ...

mv²/r = m0.9g

Solve for v , we then have

v = √0.9gmr/m

v = √0.9gr

v = √ 0.9 × 9.81 × 0.55 × 10^3

v = 69.68465m/s

We now use the equation for frequency of a period

f = v/2 π r

f = 69.68465m/s / 2 × π0.55 × 10^3

f = 0.0201 rev/seconds

Therefore revolution for a day will be

0.0201 × 24hrs × 3600

f = 1736rev/day

no

sodium is solid at rt

the skeletons of most mammals reach a certain size and then stop growing. however, many animals, including some mammals, keep growing throughout their lives. kangaroos, for example, just keep growing and growing until they die. also, the longer an animal lives the greater the chance it might catch some deadly disease.