C. hydrogen accreted onto a white dwarf from a close companion rapidly fuses to helium, releasing a large amount of energy.
The accreted material, composed mainly of hydrogen, is compacted on the surface of the white dwarf due to the intense gravitational force on that place. As material accumulates, The white dwarf becomes increasingly hot, until it reaches the critical temperature for ignition of nuclear fusion.
Answer:
441 [N].
Explanation:
Weight=mass*g, where mass=45; g=9,8.
Weight=45*9.8=441 [N].
<h2>
Answer:442758.96N</h2>
Explanation:
This problem is solved using Bernoulli's equation.
Let
be the pressure at a point.
Let
be the density fluid at a point.
Let
be the velocity of fluid at a point.
Bernoulli's equation states that
for all points.
Lets apply the equation of a point just above the wing and to point just below the wing.
Let
be the pressure of a point just above the wing.
Let
be the pressure of a point just below the wing.
Since the aeroplane wing is flat,the heights of both the points are same.

So,
Force is given by the product of pressure difference and area.
Given that area is
.
So,lifting force is 
Carbon is the answer. IF oxygen were on the list it would also be correct but for this its Carbon<span />