11. A boy on a 2.0 kg skateboard initially at rest tosses an 8.0 kg jug of water forward. If the jug has a speed of 3.0 m/s relative to the ground and the boy and skateboard move in opposite directions at 0.60 m/s, find the boy’s mass.

a and b sometimes have a positive value

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.

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