A spring scale exerts a net force of 8.5 N on an object. What is the object's mass if it has an acceleration of
3.9 m/s2?

mass of the object is 2.18 kg

Explanation:

Given

Force (F) = 8.5 N = 8.5 kg.m/

acceleration (a) = 3.9 m/

Mass (m) = ?

We know that the newton's second law of motion gives the relation between mass of ab object. force acted upon and the amount the object is accelerated. It is expressed in the form of an equation:

F = ma

mass, m = F/a

               =

               = 2.18 kg

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.