Please help me I need this for a test

Why are different constellations<br> of stars seen during different<br> seasons?

slamgirl [31]

Actually, they're not. There's a group of stars and constellations arranged
around the pole of the sky that's visible at any time of any dark, clear night,
all year around. And any star or constellation in the rest of the sky is visible
for roughly 11 out of every 12 months ... at SOME time of the night.

Constellations appear to change drastically from one season to the next,
and even from one month to the next, only if you do your stargazing around
the same time every night.

Why does the night sky change at various times of the year ? Here's how to
think about it:

The Earth spins once a day. You spin along with the Earth, and your clock is
built to follow the sun . "Noon" is the time when the sun is directly over your
head, and "Midnight" is the time when the sun is directly beneath your feet.

Let's say that you go out and look at the stars tonight at midnight, when you're
facing directly away from the sun.

In 6 months from now, when you and the Earth are halfway around on the other
side of the sun, where are those same stars ? Now they're straight in the
direction of the sun. So they're directly overhead at Noon, not at Midnight.

THAT's why stars and constellations appear to be in a different part of the sky,
at the same time of night on different dates.

5 0

4 years ago

Read 2 more answers

Complete the following:

Serga [27]

Answer:

the light will reflect parallel to the principal axis

8 0

2 years ago

Why are chemicals and hot objects never placed directly on the balance pan?

natita [175]

The answer is to retain the balance pan clean and to keep chemicals from mixing with other chemicals. Also some chemicals can respond with the metal of the balance pan and cause it to oxidize or corrode. Each time you use the balance pan, use weighing paper or a small dish or beaker to weigh out chemicals.

6 0

3 years ago

Erickson’s psychosocial stages emphasize

Musya8 [376]

This question is true because it just is

4 0

3 years ago

A boulder is raised above the ground, so that its potential energy relative to the ground is 200 J. Then it is dropped. Estimate

babymother [125]

Answer:

200 J

Explanation:

In this problem, I assume there is no air resistance, so the system is isolated (=no external forces).

For an isolated system, the total mechanical energy is constant, and it is given by:

$E=KE+PE$

where

KE is the kinetic energy

PE is the potential energy

The kinetic energy is the energy due to the motion of the object, while the potential energy is the energy due to the position of the object relative to the ground.

At the beginning, when the boulder is raised above the ground, its height above the ground is maximum, while its speed is zero; it means that all its mechanical energy is just potential energy, and it is:

$E=PE_{max}=200 J$

As the boulder falls down, its altitude decreases, so its potential energy decreases, while the speed increases, and the kinetic energy increases. Therefore, potential energy is converted into kinetic energy.

Eventually, just before the boulder hits the ground, the height of the object is zero, and the speed is maximum; this means that all the energy has now converted into kinetic energy, and we have

$E=KE_{max}=200 J$

Therefore, the kinetic energy just before hitting the ground is 200 J.

6 0

3 years ago