Showing posts with label force. Show all posts
Showing posts with label force. Show all posts

Tuesday, October 25, 2011

Moving Things with Force

Force is that which causes a free body to undergo acceleration.

There are four fundamental  forces in Nature. 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. 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 so it looks like Ben Kenobi got it partly right. Force makes our existence possible.

Monday, October 10, 2011

The Physics of 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.

The starting principle of Newton's 3rd law is the law of conservation of momentum The law of 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.

This law is commonly seen in rockets as 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

Friday, October 7, 2011

Newton's Second Law of Motion and Physics

Newton's 2nd Law of Motion 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.

Newton's 2nd Law shows that a force being applied to a mass produces a steady increase in speed. Furthermore decreasing the mass and increasing the force produces a faster increase in speed and increasing the mass and decreasing the force produces a slower increase in speed.

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

Thursday, October 6, 2011

The Important law of Physics Newton's first Law of Motion

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.

Friday, September 30, 2011

Collisions as Used in Physics

An event in which two or more bodies exert relatively high forces on each other for a short period of time is called a collision.

A collision in which the total kinetic energy of the particles before and after the encounter is the same is called elastic collision.

A collision in which the total kinetic energy of the particles before and after the encounter is not the same is called inelastic collision.

The danger of collisions results from the sudden high acceleration whic can damage equipment, cause injuries and even kill. It can cause damage from the deformation of object. It can cause colliding objects to shatter and fly apart at high speeds.

On the other hand collisions can hammer nails. They are used in sports such as pool, golf, and baseball. They have also been used to probe the makeup of matter by way of near light speed collisions inside particle accelerators.

In conclusion collisions are sudden interactions that can be elastic or inelastic. They can be dangerous and destructive but yet they can be useful.