To add vectors we can use the head to tail method (Figure 1).
Place the tail of one vector at the tip of the other vector.
Draw an arrow from the tail of the first vector to the tip of the second vector. This new vector is the sum of the first two vectors.
Answer: The period of a spring if it has a mass of 5 kg and a spring constant of 6 N/m is 5.73 sec.
Explanation:
Given: Mass = 5 kg
Spring constant = 6 N/m
Formula used to calculate period is as follows.

where,
T = period
m = mass
k = spring constant
Substitute the values into above formula as follows.

Thus, we can conclude that the period of a spring if it has a mass of 5 kg and a spring constant of 6 N/m is 5.73 sec.
<span>Oxygen and Nitrogen would be the most similar of the elements listed, because they are the closest in the periodic table. This isn't a very good reason for anything, but the two do have some similar properties. They are both non-metals, they are both highly electronegative, they are both diatmoic gasses in their natural states, they have a similar number of valence electrons, they are both generally oxidizing agents. Oxygen and Chlorine are also quite similar, but not quite as similar as Oxygen and Nitrogen.</span>
I believe one of these are called Elliptical, Spiral, and Irregular Galaxies.