Charge q is 1 unit of distance away from the source charge s. charge p is two times further away. the force exerted between s and q is the force exerted between s and p.
a. 1/2
b. 2 times
c. 1/4
d. 4 times

Answer : The correct option is, (d) 4 times

Solution :

According to the Coulomb's law, the electrostatic force of attraction or repulsion between two charges is directly proportional to the product of the charges and is inversely proportional to the square of the distance between the the charges.

Formula used :

where,

F = electrostatic force of attraction or repulsion

= Coulomb's constant

and are the charges

r = distance between two charges

First we have to calculate the force exerted between S and q when the distance between the charge is 1 unit and let us assumed that the charge be 'q'

      ..........(1)

Now we have to calculate the force exerted between S and p when the distance between the charge is 2 unit at the same charge.

    ...........(2)

Equation equation 1 and 2, we get

Therefore, the force exerted between S and q is 4 times the force exerted between S and p.

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.

1 the 4 is sig