If stretching a spring 3.50m causes a force of 20.0N, what is the spring constant of the spring? A. 5.71 N/m
B. 70.O N/m
C. 16.5 N/m
D. 23.5 N/m ​

A

Explanation:

Remark

One of the handiest things to know in physics is something called dimensional analysis.

Look at the answers you are given. All of them are in N/m. That means 2 things.

No conversions are necessary

You divide Newtons / meters. You don't need to worry too much about a formula.

But if need a formula, it is F = k * x and you need k

x = 3.5 m

F = 20.0 N

k = F / x

k = 20.0/3.5

k = 5.71 to 3 places.

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.