The primary source would be the original article published in a scientific journal. All other choices would be based on information from the original article.
Newspapers would only pick up the information from the journal itself, or from the authors. Books follow after the original article, after it has gained momentum among the research community. The public lecture at a museum would be based on work from the journal article.
A supernova is a star that suddenly increases greatly in brightness because of a catastrophic explosion that ejects most of its mass.
It lasts 29 1/2 days.
-the sidereal month- is the true period of the moon's revolution around Earth. It lasts 27 1/3 days.
-the difference of 2 days between the synodic and sidereal cycles is due to the Earth- moon system also moving in an orbit around the sun.
Answer:
C. 5.6 × 10^11 N/C
Explanation:
The electric field 
at a distance 
from a charge 
is given by
where 
is the coulomb's constant.
Now, in our case
;
therefore,
which is choice C from the options given<em> (at least it resembles it).</em>
Answer:
The correct answer is 24.
Explanation:
