1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
kirza4 [7]
4 years ago
6

When you observe a distant galaxy whose photons have traveled for 10 billion years before reaching earth we are seeing that gal?

Physics
1 answer:
expeople1 [14]4 years ago
8 0
In reality we don't see the galaxy we see it's reflection .. the light hits or got emitted by the star travel all the way long to hit our eyes .. we see their reflection . everything around you that you see is it's reflection
You might be interested in
Help with these please someone
Mice21 [21]

Answer:

Five: B

Ten: A

Explanation:

Five

An alpha decay looks like this.

A^x_y====> B^{x-4}_{y - 2}+alpha^4_2

So whatever is produced must have a mass of 4 less than 234 and a number on the periodic table of 2 less than 92. In other words, B has a mass of 230 and a number on the periodic table of 90.

The answer should be Thorium which is B.

Ten

There is actually not enough information to do 10. You get it by making an assumption and seeing if it works.

In general a beta decay can (the most common one ) look like this.

A^x_y====> B^{x}_{y-1}+Beta^0_{-1}

Is there anything that looks like that?

The weight stays the same (234) and the atomic number of the mother element (on the left) is 1 lower than the given chemical on the right.

Th^{234}_{90}====> Pa^{234}_{91}+Beta^0_{-1}

The answer is Thorium A

Beta decays are very tricky. Be very careful how you handle them. One of three items can be what is decayed. I have assumed it was an electron, but there are two other possibilities. I won't confuse you by adding them. Just be aware that they exist.

3 0
3 years ago
A ball, initially at rest, reaches a speed of 20 m/s at the bottom of the apparatus. If it takes the ball 10 seconds to reach th
MariettaO [177]

Answer:

2 m/s²

Explanation:

Given:

v₀ = 0 m/s

v = 20 m/s

t = 10 s

Find: a

a = (v − v₀) / t

a = (20 m/s − 0 m/s) / 10 s

a = 2 m/s²

3 0
3 years ago
On her camping trip, Penelope was in charge of collecting firewood. The firewood she found had a mass of 120 g and a volume of 4
zloy xaker [14]
From the formula: density=mass/volume
But first, we have to convert the cm³ to m³ by multiplying the value in cm³ by 10^-6, by so doing we'll have the volume to be 0.48*10^-3cm³.
we will also need to convert the mass which is in g to kg by simply dividing by 1000 so the mass becomes 0.12kg
Now we can solve for the density using the formula I earlier stated which is the mass divided by the volume =0.12/0.48*10^-3 so the density will be 0.25*10^3kgm-3 or 2.5*10^2kgm-3
3 0
3 years ago
Why is it possible to see yourself in a object that reflects light, but not in one that scatters light
dedylja [7]
I think it is because in objects that reflect light, the light is bounces/reflects off the object in one direction and one angle, and hits your eye, causing it to be processed as a reflection of yourself in your brain. But in one that scatters light, it bounces/reflects off in many different directions. Due to this, your brain may not process it as a reflection.
Here is a little bit of extra info:
https://www.sciencelearn.org.nz/resources
7 0
3 years ago
Which element makes up earth's atmosphere?
Mrrafil [7]
The answer is D.nitrogen. the atmosphere is mostly made up of nitrogen.(95% is nitrogen) and (2% <span>oxygen</span>) and and (3% of other gases)
7 0
3 years ago
Other questions:
  • The illustration shows a light ray striking an object.
    13·1 answer
  • Please help on this one
    13·1 answer
  • An object in free fall is dropped from a building. Its starting velocity is 0 m/s. Ignoring the effects of air resistance, what
    9·1 answer
  • A parallel-plate capacitor is connected to a battery. What happens to the stored energy if the plate separation is doubled while
    7·1 answer
  • A woman parked on a slight incline observes that the car beside her starts moving forward at approximately 0.30 m/s. When she lo
    6·2 answers
  • Describe Why is it difficult for a human to travel long distance in space
    14·1 answer
  • Which of these binary systems is most likely to contain a black hole?A.An x-ray binary containing an O star and another object o
    7·1 answer
  • The temperature of the surface of the Sun is 5500°C.
    8·1 answer
  • The purpose of a cell phone cover is to protect your phone from impact forces. How does a cell phone case do this?
    8·1 answer
  • Q/C S Starting with the definition of work, prove that at every point on an equipotential surface, the surface must be perpendic
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!