It has been suggested that rotating cylinders about 12.5 mi long and 6.25 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 on Earth?

w = 0.0436 rad/s

Explanation:

Radius of the cylinder is

3.125 * 1609m/mile = 5028 m

Using the angular acceleration formula, we have

a = v²/r = w²r.

Since we're interested in the angular speed, we make w the subject of the formula, so that

w² = a/r

w = √a/r

w = √(9.8/5028)

W = √0.0019049

w = 0.0436 rad/s

Then we can conclude that the angular speed of the rotation is w = 0.0436 rad/s

answer: at 24 february, 2014 the population gets twice of its initial population.

explanation:

since we have given that

the population for alpha city, t years after january 1, 2004 is given as

first we find out the initial population, i.e. t=0,

so, our quadratic equation becomes,

according to question, we have said that if the population has twice its initial population, then it becomes

so, time taken to reach this above mentioned population is given by

now, we know that time can't be negative so, we take t=9.149 years.

hence, at 24 february, 2014 the population gets twice of its initial population.