Answer:
1. Least massive stars are the coolest and least luminous, lower right of main sequence, on HR diagram.
2. Most massive are the hottest and most luminous, upper left of main sequence on Hr Diagram.
3. The radius of stars are related to their sprectral type. having the O being the hottest upper left and M being the coolest bottom right.
Answer:
Explanation:
There's a formula for this:

F being force, k being the spring constant, and displacement being the change in x
We are given the force and the spring constant, so this is essentially isolating the Δx term. Do 60N/120N per meter. The newtons cancel out and you get a final answer of Δx = 0.5 meters
Answer:
We have a not significant increase of the population until 1700s or 1800s and then a significant increase growth from these years to the present.
Explanation:
From the figure attached we see the evolution of the human population since early times (1050).
We see that from 1050 until 1750-1850 we have an increase slowly with a low value for the increase per year.
But after these years (1750-1850) we see a considerable increase of the population, like an exponential model.
So then we can conclude in general terms this:
We have a not significant increase of the population until 1700s or 1800s and then a significant increase growth from these years to the present.
The velocity is a vectorial quantity, whereas speed is a scalar quantity, meaning it depends on the direction!
As such, the velocity is changing because the direction is changing.