Explanation:
According to formula
g = GM/R^2
when mass is halved the value of g becomes half but when radius is halved the value of g increases 4 times.
As a result of both value of g becomes twice.
Total mass of the Sun = 2x10^30kg
<span>So 76% of that = (2x10^30kg)*(0.76) = 1.52x10^30kg ----> total amount of Hydrogen i</span><span>f only 12% of that is used for fusion, then (1.52x10^30kg)*(0.12) = 1.82x10^9kg</span>
To find this we should use the equation Ek=1/2mv^2 where Ek is the kinetic energy, m is the mass and v is the velocity. So by this Ek=1/2*1*30^2 which then makes Ek=450 joules