E mass number of any given atom depends solely on the number of protons and neutrons in its nucleus. The mass number of any atom can be determined by adding the number of protons and neutrons. (Mathematically this is stated as Mass Number = Protons + Neutrons). For instance, a Carbon atom with 6 protons and 6 neutrons will have a mass number of 12AMU. However, a Carbon atom with 6 protons and 8 Neutrons will have a mass number of 14AMU. They are both Carbon atoms, however they each have a different mass number. Atoms of the same element that have different numbers of neutrons, and therefore, different mass numbers, are called isotopes. Isotopic symbols are used to indicate isotopes of the same elements. In the following isotopic symbols the lower number is the atomic number…it is the number of protons. The upper number is the mass number, it represents to sum of the protons and neutrons in the atoms nucleus.
To solve the problem it is necessary to use Newton's second law and statistical equilibrium equations.
According to Newton's second law we have to

where,
m= mass
g = gravitational acceleration
For the balance to break, there must be a mass M located at the right end.
We will define the mass m as the mass of the body, located in an equidistant center of the corners equal to 4m.
In this way, applying the static equilibrium equations, we have to sum up torques at point B,

Regarding the forces we have,

Re-arrange to find M,



Therefore the maximum additional mass you could place on the right hand end of the plank and have the plank still be at rest is 16.67Kg
Answer:
The index of refraction of the liquid is n = 1.33 equivalent to that of water
Explanation:
Solution:-
- The index of refraction of light in a medium ( n ) determines the degree of "bending" of light in that medium.
- The index of refraction is material property and proportional to density of the material.
- The denser the material the slower the light will move through associated with considerable diffraction angles.
- The lighter the material the faster the light pass through the material without being diffracted as much.
- So, in the other words index of refraction can be expressed as how fast or slow light passes through a medium.
- The reference of comparison of how fast or slow the light is the value of c = 3.0*10^8 m/s i.e speed of light in vacuum or also assumed to be the case for air.
- so we can mathematically express the index of refraction as a ratio of light speed in the material specified and speed of light.
- The light passes through a liquid with speed v = 2.25*10^8 m/s :

- The index of refraction of the liquid is n = 1.33 equivalent to that of water.
The answer to the question is that before the big bang, the universe was much hotter and more dense than it is now. Letter B.
It is because after the big bag occurred, the universe became cooler and less dense.
a. - does not correspond in the answer because the universe became less dense after the big bang.
c - the universe became cool and less dense after the big bang so being cool and less dense does not correspond to the question.
d - cooler does not answer the question because it only became cooler after the big bang.
Answer:
Well if it gets warmer the ice will weaken and if it gets hot enough will melt. Of course if the weather gets colder the ice will thicken.
Explanation: