Explanation:
The lines in the spectra of star is due to absorption of light emitted by star by different elements present in atmosphere of the star .
If some element is present in the outer atmosphere of he star , it will absorb a particular portion of light , for which there will be black line in the spectrum .
These are called Fraunhoffer's lines .
Now there is no such line at the place of Helium in the light spectrum . This means that Helium element is not present in the outer atmosphere of the star.
You literally just put your fingers in your genitals? is this for a sex ed course...?
All machines are not 100% efficient because of <span>C. Friction</span>
Answer:
1020 km
Explanation:
A complete rotation of the wheel equals a distance of 1 circumference.
The circumference is
where <em>d</em> is the diameter of the wheel.
300,000 rotations = 
In kilometers, this is = 1017876/1000 km = 1020 km
