Refraction is the bending of a wave when it enters a medium where its speed is different. This phenomenon is explained by the conservation of energy and conservation of momentum.
Law of Conservation of energy states the total energy of an isolated system remains constant.
law of conservation of momentum states that in a closed system the total momentum is constant.
<span>In refraction, when a medium changes, the phase velocity also changes but its frequency does not; it remains constant. </span>
From the gravity acceleration theorem due to a celestial body or planet, we have that the Force is given as

Where,
F = Strength
G = Universal acceleration constant
M = Mass of the planet
m = body mass
r = Distance between centers of gravity
The acceleration by gravity would be given under the relationship


Here the acceleration is independent of the mass of the body m. This is because the force itself depended on the mass of the object.
On the other hand, the acceleration of Newton's second law states that

Where the acceleration is inversely proportional to the mass but the Force does not depend explicitly on the mass of the object (Like the other case) and therefore the term of the mass must not necessarily be canceled but instead, considered.
The statement 'energy cannot be created or destroyed' BEST supports the idea that energy remains constant during an energy transformation. It is the first law of thermodynamics.
<h3>Law of Conservation of Energy</h3>
The law of conservation of energy, also known as the first law of thermodynamics, indicates that energy can neither be created nor destroyed.
According to this law, the energy can be interchanged from one type of energy (e.g., kinetic energy) form to another (e.g., potential energy).
The first law of thermodynamics is fundamental for understanding major science disciplines, and it is a rosetta stone in physics.
Learn more about the first law of thermodynamics here:
brainly.com/question/7107028
Answer:
A. Two protons and two neutrons.
Explanation:
Alpha particles are positively charged specie identical to the nucleus of Helium atom.