Asatellite is orbiting the earth just above its surface. the centripetal force making the satellite follow a circular trajectory is just its weight, so its centripetal acceleration is about 9.81 m/s2 (the acceleration due to gravity near the earth's surface). if the earth's radius is about 6370 km, how fast must the satellite be moving? how long will it take for the satellite to complete one trip around the earth?

Explanation:

A satellite is orbiting the earth just above its surface. The centripetal force making the satellite follow a circular trajectory is just its weight, so its centripetal acceleration is about 9.81 m/s2 (the acceleration due to gravity near the earth's surface). If the earth's radius is about 6370 km, how fast must the satellite be moving? How long will it take for the satellite to complete one trip around the earth?

The weight of the satellite is the centripetal force, so:

Which means:

We can calculate then the velocity:

For calculating how long will it take for the satellite to complete one trip around Earth we consider that the distance of the trip is the circumference of the orbit. This is calculated as .

Since velocity is v=d/t, we have:

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.