Johann Kepler analyzed planetary data collected by astronomers before him. He gave three formulas regarding the motion of the planets. These are known as Kepler’s laws. The three formulas are as follows-
First formula:
Each planet revolves in an elliptical orbit with the Sun at its epicenter.
Area formula:
The connecting lines of the Sun and the planets traverse equal areas in equal time.
Time period formula:
The square of the orbital period of each planet is proportional to the cube of the average distance of that planet from the Sun.

Mass is neither created nor destroyed, mass can only change from one form to another, – this is the law of constancy of mass. If mass must have been created at the beginning of the universe, it would be a violation of the law of constancy of mass. Does that mean that the law of constancy of mass was violated only then the universe was created? Nah, according to the zero energy hypothesis, the universe came from nothing, yes it’s very strange to us, so many people don’t understand, so let’s see how much I can explain today…

• Mass, momentum and energy, these three together make up matter. A simple definition of matter is that which is acted upon by a force. The amount of matter in an object is known by measuring its mass. The greater the mass of an object, the more force it will exert on it.

• If the object is in motion this motion is called the momentum of the object, in most cases momentum is proportional to the product of the mass of the object and the speed of the object. Being a vector quantity, the direction of momentum and the direction of motion of the object are the same.

• Another religion of matter emerges from mass and momentum, which is inertia. The heavier a stationary object is, the more energy it takes to move it.

• Another religion comes from the momentum of matter, that is energy. When the momentum of the object is zero, the energy of the object is proportional to its mass, this is called the static energy of the object. When matter is in motion, its energy exceeds static energy, this excess energy is called kinetic energy. So, if any two of these three properties, mass, momentum, and energy, are known, the other can be calculated mathematically.

Einstein’s famous formula of special relativity is E=mc2 where m is the mass of the object, which is multiplied by the square of the speed of light c to give E i.e. the energy. The speed of light is about 300,000 kilometers per second, so now you understand that if you multiply 300,000 squared by m, what mass will be converted into E (energy)! The atomic bomb is not so strong!

Another thing was understood from this –

Mass can be converted into energy, and energy also creates mass. That is, whatever mass is power! So we settled on –

Mass didn’t have to be “created” during the creation of the universe, just converted from energy to mass!

Now the next problem, just like the law of constancy of mass, energy also has a law of constancy, according to the law of constancy of energy – “Energy is neither created nor destroyed, energy can only change form, the total amount of energy in the universe is fixed and unchanging”.

So where did the energy come from at the beginning of the creation of the universe? If energy was created then the law of energy constancy was violated! But no, here is the main game! In fact, the total amount of energy in the universe is zero! Because, it turns out, in a roughly homogeneous universe all positive gravitational forces (matter) and all negative gravitational forces (gravity) cancel each other out! If a universe starts from zero, the energy value is calculated to be as much as it is supposed to be, i.e. zero. From this it is clearly understood that the universe came spontaneously from nothing.

Engineers are interested in quasi-equilibrium processes for two reasons.
First, these are easy to analyze and hence least quantitative information about the behavior of the actual systems of interest can often be developed.
Second, work-producing devices deliver the maximum work, and work-absorbing devices require minimum work when they operate on quasi-equilibrium processes. Therefore, quasi-static processes serve as standards for other processes.

The substance consists of a large no of particles called molecules. The properties of substances naturally depend on the behavior of these particles. For example, the pressure of a gas in a container is the result of momentum transfer between the molecules and the walls of the container. However, one does not need to know the behavior of the gas particles to determine the pressure in the container. It would be sufficient to attach a pressure gauge to the container. This macroscopic approach to the study of thermodynamics does not require knowledge of the behavior of individual particles. It is the overall behavior approach. It is called classical thermodynamics. It provides a direct and easy way to the solution of engineering problems.

Falling objects fall downward under the influence of gravity. So when an object falls through a liquid or gas, it drags the layers of the liquid or gas that the object comes in contact with. As a result relative velocity is created between different layers of liquid or gas. The viscosity of the medium creates a barrier against this relative motion. When this upward viscous force equals the force causing the object to move, the total effective force on the object is zero and the object continues to fall through the medium at constant velocity. This constant velocity of the falling object is called terminal velocity.

If a sphere falls under the influence of gravity through a viscous fluid, initially its velocity increases due to gravitational acceleration, but simultaneously the drag force on it increases so that the net acceleration of the object decreases. At some point the net acceleration of the object is zero. The object then begins to fall with constant velocity. Then this velocity is called terminal velocity.