pshyical change is a usually reversible change of a substance, as size or shape: Freezing a liquid is a physical change. Compare chemical change.
internal change is when the movement of the particles increases
specific latent heat is the amount of energy per kg (unit mass) required to change ice to water without change in temperature.
Answer:

Explanation:
Using the tension in the spring and the force of the tension can by describe by
T = kx
, T = mg
Therefore:

With two springs, let, T1 be the tension in each spring, x1 be the extension of each spring. The spring constant of each spring is 2k so:


Solve to x1





this is due to the existence of other forces called the strong nuclear forces that overcomes the repulsion forces between the protons and keeps the nucleons holding to each other also there is a type of energy that is called the nuclear binding energy and this energy also works on binding the components of the nucleus together