Need a small,  horizontal pipe with cross-sectional area a is joined to a large horizontal pipe with cross-sectional area 2a.  both pipes are at the same height,  and completely filled with water (density 1000  kg/m^3).  what is the speed of the water in the large pipe if the speed in the small pipe is 1  m/s?

this is poiselle's equation from fluid mechanic in physics. mech eng

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.