Answer :First part is what you learned so write what you learned then the other parts is The evidence that the universe is expanding comes with something called the red shift of light. Light travels to Earth from other galaxies. As the light from that galaxy gets closer to Earth, the distance between Earth and the galaxy increases, which causes the wavelength of that light to get longer.
Explanation: 
 
        
             
        
        
        
Answer:
The problem occurs with all spherical mirrors.
Spherical mirrors are practical up to about inches in diameter.
Reflecting telescopes use spherical mirrors for apertures up to about 4 ".
Larger aperture telescopes use parabolic mirrors to obtain sharp focus.
 
        
             
        
        
        
Wavelength = (speed) / (frequency)
Wavelength = (340 m/s) / (400 /s)
<em>Wavelength = 0.85 meter</em>
 
        
             
        
        
        
In a nuclear power plant, you start off with uranium (nuclear energy), and a lot of that nuclear energy is released by heat energy. Heat then boils water and drives a turbine for a generator, which creates kinetic energy, which produces electrical energy.
In other words, your answer is B.
        
                    
             
        
        
        
Answer:
a) I = 13.77 A
b) 0 ° or to the East
Explanation:
Part a
The magnetic field by properties would be 0 at the radius on this case r =8.1 cm.Analyzing the situation the wirde would produce a magnetic field equals in magnitude to the magnetic field on Earth by with the inverse direction. 
The formula for the magnetic field due to a wire with current is:

In order to have a value of 0 for the magnetic field at the radius then we need to have this balance
B (r=8.1) = B (Earth)
Replacing:
 
 
Solving from I, from the last equation we got:

 = 13.77 A
 = 13.77 A
Part b
We can use the right hand rule for this case.
The magnetic field of the wire would point to the South, because the magnetic field of the earth given points to the North. Based on this the current need's to flow from West to East in order to create a magnetic field pointing to the south, because the current would be perpendicular to the magnetic field created.