Answer:
b. 
Explanation:
As we know that the electric field due to infinite line charge is given as

here we can find potential difference between two points using the relation

now we have

now we have

now plug in all values in it


now we know by energy conservation


Answer:
f = q
Explanation:
In the attachment we can see a diagram of the parallel rays.
The dotted line represents the normal to the mirror surface
These rays when reflected using the constructor equation
where p and q are the distance to the object and the image respectively.
Since the rays are parallel P = inf
1 / f = 1 / inf + 1 / q
f = q
this means that all the rays focus on one focal point.
A good heat insulator absorbs all, or almost all, of the heat energy
from any heat that flows through it.
A good electrical insulator absorbs all, or almost all, of the energy
from any electric current that flows through it.
Answer:
r = 6.4 cm
Explanation:
F = GMm/r²
r = √(GMm/F)
r = √((6.674e-11)(6.2e5)(13e3)/130)
r = 0.06432... m
Those are some high density materials!
The
sun is a ball of hot gases containing different kinds of elements at different
cores. It has a very high temperature that radiates all throughout the Milky
Way galaxy. The sun has three main parts; photosphere, chromospheres
and corona. The outer core of a star located at the chromospheres contains
mostly of hydrogen. Inside the hydrogen is helium then carbon, oxygen, neon,
magnesium silicon and the inert gas. The photosphere is scattered by the loose electrons in the corona’s plasma.