The Earth's average density a. can be deduced from its volume and gravitational pull. b. is the same as rocks on the surface. c. is greater than that of an iron meteorite. d. is about the same as the core.

option A

Explanation:

Earth density can be deduced with the help of gravitational pull and the volume.

gravitational pull of the earth is equal to= ........(1)

We know, the volume of the earth, with the help of that we can calculate radius of the earth.

We know gravitational pull on earth = 9.8 m/s²

From equation (1) we can calculate the mass.

So, Density = mass/ Volume.

From the above expression we can calculate the density of earth.

Hence, the correct answer is option A

c

explanation:

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.