Relativity Basics

 

References

Basic Relativity

Introduction to Relativity

An Introduction to Relativity

Moving Things by Force

That which causes a free body to undergo acceleration is called foece.

There are four fundamental forces in Nature. They are gravity which is the mutual attraction of all matter in the universe it is what holds you to the Earth, electromagnetism which is the mutual attraction and repulsion of charged partials, the weak nuclear force is that which regulates types of nuclear decay such as Bata decay by overcoming the strong nuclear force and the strong nuclear force is the binding force that holds the atomic nucleus together against the tendency of positively charged protons.

Force causes mater to accelerate which is the main function of force by definition. It can be used to overcome other forces such as friction gravity. Force also holds things together since the electromagnetic force holds an object together including your body and the strong nuclear force holds atomic nuclei together. It can break things apart such as bombs or the force resulting from ramming two things together which can cause them to shatter and the peaces to fly apart.
Regardless of its source force causes acceleration. Force can also stop acceleration by resisting another force. Force holes thing together so force does indeed bind us together

Physics and Newton's Third Law of Motion

Newton's 3rd law states that for every action there is an opposite and equal reaction. Put another way when you push on an object it pushes you back.

Newton's 3rd law starts with conservation of momentum Conservation of momentum states  that the total change in a system’s motion to be zero. As a result moving a mass requires moving another mass in the opposite direction.

Rockets are the best example and the flame that is seen coming from the bottom of the rocket is propellant mass that is being ejected from the engines. This mass provides the action whose reaction pushes the rocket forward. Jets work on same basic principle but the main differ deference between a jet and a rocket is that jets take in air as part of their propellant mass making them more efficient than rockets since they are nor required to carry all that mass onboard.

The basic concept of Newton's 3rd law is that two masses push on each other with equal force. Equal mass will move away at the same speed. When one mass is smaller the other and if the force is kept the same, the smaller mass moves away faster and the heavier mass moves at the same speed as before. If one keeps the masses the same as in the last example but this time the force is larger then they both fly apart faster. The smaller mass still moves much faster than the larger mass.

One thing that is a little counter interactive is the fact that when a car that is being driven down the road, the Earth is actually being pushed in the opposite direction. To be fair this affect is extremely small but it is sill not zero and the traffic that is going opposite direction averages out to zero net force. It gets even stranger since even when you are just walking around you are actually pushing the Earth in the opposite direction. Once again it is still an extremely small, in fact much smaller than in a car; but still not zero. Furthermore all the people and animals in the world the affect will still average out to be zero. Like wise when a planet moves around its star the planet pulls back on the star causing it to wobble slightly. This is a main way that extra Solar planets are detected.  

Newton's 3rd law of Motion boils down to the fact that when one object pushes on another object, the second object pushes back. It is an important part of every change in motion in the universe because with out it no changes in motion would ever occur in the universe.

Newton's Second Law of Motion and Physics

The principle that states that a mass acted on by a force undergoes acceleration in the direction of the force, with a magnitude inversely proportional to the mass and proportional to the force is called  Newton's 2nd Law of Motion.

According to Newton's 2nd Law a force that is applied to a mass produces a steady increase in speed. Also decreasing the mass and increasing the force produces a faster increase in speed, while increasing the mass and decreasing the force produces a slower increase in speed.

Every change in motion in the Universe is based on Newton's 2nd Law including both changes in speed and direction. It is indeed fundamental to understanding of motion since without it changes in motion can not be properly understood.

Newton's first Law of Motion an important law of Physics

Newton's 1st Law of Motion states that a body will remain in motion or remain at rest unless it is acted on by an out side force. This law is also known as the law of inertia because inertia is the resistance to changes in motion. Newton's first Law shows that an object continues to move without changes in its motion until a force is imparted on it.

Every movement we make uses of Newton's 1st Law. Without the fist law of motion controlling motion is probably not even be possible. All possible methods of controlling motion depend on the first law. The 1st law of motion shows that motion remains the same without an outside force. We use it in every move we make.

Newton's Laws of Motion They Really Move

The three basic physical laws of classical mechanics are called Newton's Laws of Motion. They describe the relationship between a body, the forces acting on it andhow that affects the resulting motion.

Newton's First law says a body will remain in rest or in motion unless acted on by an out side force. It is also known as the law of inertia since inertia is the resistance to changes in motion.

Newton's Second law says a mass acted on by a force undergoes acceleration in the direction of the force, with a magnitude inversely proportional to the mass and proportional to the force.

Formula

f = ma

f   = force

m = mass

a  = acceleration

Newton's Third law states that for every action there is an opposite and equal reaction.  Put another way when you push on an object it pushes you back. This is the bases of rockets and jets.

 These three laws along with gravity form the cornerstone of modern physics. Not much outside quantum mechanics makes since with out them. They affect every aspect of our lives and are involved in some way with every thing we do.

 The three laws are most evident in space flight. The 3rd law provides force to move a rocket, the 2nd law turns that force into acceleration and the 1st law keeps a space craft in obit or moving through deep space.

In conclusion Newton's Laws of Motion are the three basic physical laws of classical mechanics. They affect every aspect of our lives, in fact we use them every time we move.

An Introduction to Physics

Physics is the study of matter, and energy and their interactions. Physics is more than formulas that you may not be able to make sense of. While physic is scientifically expressed by formulas, it is more than the formulas. It can take the form of practical experience. 

Whether you know it or not physics found is in sports Baseball is a prime example of physics in sports, specifically ballistics. Pool is another example of physics in sports specifically collision physics 

The two main founders of physics are Galileo Galilei and Isaac Newton. These two are the main men responsible for establishing modern physics, there were others involved but they were the main ones.

Physics is central to all other physical sciences including Astronomy, Biology, Chemistry, Cosmology and Geology.  Physics has shown us much about the structure of matter, the nature of Energy and the nature of space and time. Physics has the potential to shown us how the universe works and the nature of reality itself.