Answer:
First, as you may know, the light travels at a given velocity.
In vaccum, this velocity is c = 3x10^8 m/s.
And we know that:
distance = velocity*time
Now, if some object (like a star ) is really far away, the light that comes from that star may take years to reach the Earth.
This means that the images that the astronomers see today, actually happened years and years ago (So the night sky is like a picture of the "past" of the universe)
Also, for example, if an astronomer sees some particular thing, he can apply a model (a "simplification" of some phenomena that is used to simplify it an explain it) and with the model, the scientist can infer the information of the given thing some time before it was seen.
Answer:
its direction is changing
1. medium
2. Type
3. Temperature
Just took the quiz
Answer:
19 m/s
Explanation:
The complete question requires the final speed to be calculated.
Velocity is the rate and direction at which an object moves. Acceleration is the rate of change of velocity per unit time and can be calculated by the difference in velocity over a given time.
For this question, first the unknown acceleration must be calculated and used to determine the final velocity
Step 1: Calculate the acceleration




Step 2: Calculate the velocity using the acceleration calculated above



Answer:
0.000003782 m
0.000001891 m
0.000001197125 m
Explanation:
= Wavelength = 248 nm
D = Diameter of beam = 1 cm
f = Focal length = 0.625 cm
The angle is given by

The width is given by

The required width is 0.000003782 m
Minimum resolvable line separation is given by

The minimum resolvable line separation between adjacent lines is 0.000001891 m
when 

The new minimum resolvable line separation between adjacent lines is
