Answer:
the correct answer is the 60

Before getting an answer for it first we have to understand nuclear fusion.
Nuclear fusion is a thermo-nuclear reaction in which two light unstable nuclei will form a heavy stable nuclei. In this process there will be some mass defect which will be converted into energy as per Einstein's mass energy equivalence theorem.
The theorem is stated as
where c is the velocity of light and m is the mass converted into energy.
One take an example of fusion in sun where 4 hydrogen atoms combine to form a helium nucleus which are explained below-



-----------------------------------------------------------------------
Here
is the positron.
In this process very high temperature is needed which is approximately equal to the temperature of the sun i.e 
Such temperature is very difficult to initiate the reaction on the earth surface. It should be carried out in an sustainable way also .Otherwise It will cause nuclear hazards.
I'm gonna have to assume the girl is on the right side and boy on left.
The net force is the sum of all forces on an object (includes negatives).
Let's say the force of the boy is variable <em>b</em>. Use the formula F = ma.
<em>b </em>+ 3.5 = 0.2(2.5)
This is now simple algebra. Solve to get that <em />the boty is exerting a force of -3N to the left.
Answer:
6.214g/cm³
Explanation:
The question is on density of a material
Density=mass/volume
Given, mass=87grams and volume= 14 cm³ density=?
Density=m/v 87/14 =6.214g/cm³