It has been suggested that rotating cylinders about 10 mi long and 4.9 mi in diameter be placed in space and used as colonies. What angular speed must such a cylinder have so that the centripetal acceleration at its surface equals the free-fall acceleration?

you grab the diameter divide it by 2

4.9 / 2 = 2.450
You them grab the answer above and covert it (miles to meters) by multiplying it by 1609.34
2.45 x 1609.34 =

after you have the answer for above square root it and that will give you the final answer in rad/s

To find the angular speed that the cylinder must have, we can start by understanding the given information. The suggestion is to place rotating cylinders in space and use them as colonies. The dimensions given for the cylinder are 10 mi long and 4.9 mi in diameter.

The centripetal acceleration at the surface of the cylinder is equal to the free-fall acceleration. In other words, the acceleration experienced by an object on the surface of the rotating cylinder should be equal to the acceleration due to gravity.

The formula for centripetal acceleration is given by:
a = ω²r

Where:
- a is the centripetal acceleration
- ω is the angular speed (in radians per second)
- r is the radius of rotation

In this case, the radius of rotation is half the diameter of the cylinder, so r = (4.9 mi) / 2 = 2.45 mi.

The free-fall acceleration on Earth is approximately 32.2 ft/s².

To convert the dimensions to feet, we can use the conversion factor: 1 mile = 5280 feet.

Hence, the radius of rotation in feet is:
r = 2.45 mi * 5280 ft/mi = 12,936 ft

Now we can plug the values into the formula and solve for ω:
32.2 ft/s² = ω² * 12,936 ft

Rearranging the equation to solve for ω, we have:
ω² = (32.2 ft/s²) / (12,936 ft)
ω² ≈ 0.002486 rad/s²

Taking the square root of both sides, we get:
ω ≈ 0.050 rad/s

Therefore, the angular speed, approximately, that the cylinder must have is 0.050 radians per second.