Which scenario would result in a drop in the pitch being observed? The observer moves closer to a stationary source.
The source moves toward a stationary observer.
A source moving toward an observer suddenly stops.
The observer and the source move in the same direction at the same speed.

the answer is to check all of them! they all apply well at least i think so!

none, its a machine

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.

i believe the answer is a hope it and is correct