Future Experts come here and share their knowledge base and concepts with each other. Every article submitted is reviewed by experts. Nickels are awarded to articles in terms of authenticity, relevance, clarity and presentation.
Electric Field and the Movement of Charge Perhaps one of the most useful yet taken-for-granted accomplishments of the recent centuries is the development of electric circuits. The flow of charge through wires allows us to cook our food, light our homes, air-condition our work and living space, entertain us with movies and music and even allows us to drive to work or school safely.We will explore the reasons for why charge flows through wires of electric circuits and the variables which affect the rate at which it flows. The means by which moving charge delivers electrical energy to appliances in order to operate them will be discussed in detail. &nbs
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submitted by kane (2199 m) on 31 May 2008 19:40:18 IST (12 comments 278 views)
Momentum Conservation in Explosions For collisions occurring in isolated systems, there are no exceptions to momentum conservation.This same principle of momentum conservation can be applied to explosions. In an explosion, an internal impulse acts in order to propel the parts of a system (often a single object) into a variety of directions. After the explosion, the individual parts of the system (which is often a collection of fragments from the original object) have momentum. If the vector sum of all individual parts of the system could be added together to determine the total momentum after the explosion, then it should be the same as the total momentum before th
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submitted by kane (2199 m) on 9 Mar 2008 21:53:52 IST (21 comments 608 views)
In a collision, an object experiences a force for a given amount of time which results in its mass undergoing a change in velocity (i.e., which results in a momentum change). There are four physical quantities mentioned in the above statement - force, time, mass, and velocity change. The force multiplied by the time is known as the impulse and the mass multiplied by the velocity change is known as the change in momentum. The impulse experienced by an object is always equal to the change in its momentum. In terms of equations, this was expressed as This is known as the impulse-momentum change theorem. As an effort is mad
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submitted by kane (2199 m) on 29 Feb 2008 20:21:33 IST (26 comments 737 views)
Momentum The sports announcer says "Going into the all-star break, the Chicago White Sox have the momentum." The headlines declare "Chicago Bulls Gaining Momentum." The coach pumps up his team at half-time, saying "You have the momentum; the critical need is that you use that momentum and bury them in this third quarter." Momentum is a commonly used term in sports. A team that has the momentum is on the move and is going to take some effort to stop. A team that has a lot of momentum is really on the move and is going to be hard to stop. Momentum is a physics term; it refers to the quantity of motion that an object has. A sports team which is on t
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submitted by kane (2199 m) on 20 Feb 2008 13:17:46 IST (15 comments 307 views)
Inertia and Mass Newton's first law of motion states that "An object at rest tends to stay at rest and an object in motion tends to stay in motion with the same speed and in the same direction unless acted upon by an unbalanced force." Objects tend to "keep on doing what they're doing." In fact, it is the natural tendency of objects to resist changes in their state of motion. This tendency to resist changes in their state of motion is described as inertia. Inertia: the resistance an object has to a change in its state of motion. Newton's conception of inertia stood in direct opposition to more popular conceptions about mot
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submitted by kane (2199 m) on 7 Jan 2008 22:19:05 IST (14 comments 241 views)
Types of Forces A force is a push or pull acting upon an object as a result of its interaction with another object. There are a variety of types of forces. Contact Forces Action-at-a-Distance Forces Frictional Force Gravitational Force Tension Force Electrical Force Normal Force Magnetic Force Air Resistance Force Applied Force Spring Force Type of Force (and Symbol) Description of Force Applied Force Fapp An applied force is a force which is applied to an object by a person or another object. If a person is pushing a desk a
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submitted by kane (2199 m) on 31 Jan 2008 10:18:31 IST (21 comments 587 views)
Balanced and Unbalanced Forces Newton's first law of motion has been frequently stated throughout this lesson. An object at rest tends to stay at rest and an object in motion tends to stay in motion with the same speed and in the same direction unless acted upon by an unbalanced force. But what exactly is meant by the phrase unbalanced force? What is an unbalanced force? In pursuit of an answer, we will first consider a physics book at rest on a table top. There are two forces acting upon the book. One force - the Earth's gravitational pull - exerts a downward force. The other force - the push of the table on the book (sometimes
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submitted by kane (2199 m) on 9 Jan 2008 22:16:17 IST (3 comments 135 views)
Newton's first law of motion is often stated as An object at rest tends to stay at rest and an object in motion tends to stay in motion with the same speed and in the same direction unless acted upon by an unbalanced force. There are two parts to this statement - one which predicts the behavior of stationary objects and the other which predicts the behavior of moving objects. The two parts are summarized in the following diagram. The behavior of all objects can be described by saying that objects tend to "keep on doing what they're doing" (unless acted upon by an unbalanced force). If at rest,
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submitted by kane (2199 m) on 5 Jan 2008 23:07:27 IST (2 comments 142 views)
Inorganic and Organic Molecules Inorganic molecules are substances that don?t have carbon-hydrogen (C-H) bonds. They are generally simple and are not normally found in living things. Organic molecules, substances that contain carbon-hydrogen bonds, are found in living things. The major classes of organic molecule include carbohydrates, proteins, lipids and nucleic acids. Amino Acids Proteins are polymers composed of monomers called amino acids. Each amino acid contains contain a? base amino group ( -NH2) acidic carboxyl group ( -COOH) hydrogen atom ?all attached to same carbon atom (the ??carbon or alpha carbon). A fourth bond attaches ?-carbon
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submitted by kane (2199 m) on 13 Dec 2007 23:15:18 IST (5 comments 138 views)
Potential Energy Potential energy is the ability an object possesses to cause change based on its position. By winding a spring it has more ability to do something than when it is unwound. The spring is not actually doing anything, but it could. This is the nature of potential energy. The potential energy we use the most is gravitational potential energy. This is the energy an object has due to its position from the center of the earth. If there were no gravitational force, there would be no gravitational potential energy. Since work causes a change in potential energy, the amount of gravitational potential energy an
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submitted by kane (2199 m) on 3 Dec 2007 22:29:41 IST (6 comments 166 views)
Potential Energy Potential energy is the ability an object possesses to cause change based on its position. By winding a spring it has more ability to do something than when it is unwound. The spring is not actually doing anything, but it could. This is the nature of potential energy. The potential energy we use the most is gravitational potential energy. This is the energy an object has due to its position from the center of the earth. If there were no gravitational force, there would be no gravitational potential energy. Since work causes a change in potential energy, the amount of gravitational potential energy an
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submitted by kane (2199 m) on 3 Dec 2007 22:29:41 IST (6 comments 166 views)
Conservation of Energy As with momentum, energy is conserved in all interactions. The general rule of the universe is that energy cannot be created or destroyed, just changed from one form to another. In the early twentieth century this definition was expanded to include mass as well as energy since they are two forms of the same thing. In this course we will only deal with energy conservation and assume the mass stays the same. TEbefore = TEafter Elasticity is a term which refers to the amount of mechanical energy conserved in an interaction between objects. If there is no loss of mechanical energy then the interaction is said
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submitted by kane (2199 m) on 8 Dec 2007 15:35:02 IST (3 comments 145 views)
Changes in Energy As before, an object cannot do anything to itself to change the total amount of energy, but the energy can move between potential and kinetic. Total energy = potential energy + kinetic energy TE = PE + KE The total energy may remain constant, but the potential and kinetic energies may not. Think about you car coasting up a hill. The higher it goes, the slower it goes. (kinetic energy changing into potential e
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submitted by kane (2199 m) on 6 Dec 2007 23:05:39 IST (4 comments 128 views)
Kinetic Energy Kinetic energy is determined by the motion of the object. If an object is moving it will exert a force on anything it interacts with. This force would do work on the other object. If an object is not moving it has no ability to run into another object and do work.This is the nature of kinetic energy. The formula for calculating the kinetic energy of an object is: KE = 1/2 m V2 Once again we see a combination of the object?s mass and velocity, similar to momentum. Momentum was a vector, but kinetic energy is not. Again, you will not have to use vector procedures to work with kinetic energy. Ther
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submitted by kane (2199 m) on 5 Dec 2007 22:43:49 IST (1 comments 109 views)
The Concept of Energy Reduced to simplest terms, the universe is nothing more than a series of energy exchanges. As in much of physics, the concept of energy is easy to understand, but difficult to express and work with. Energy = The ability to cause change. Notice the simplicity of this definition. If something has the ability to cause a change in the physical or chemical properties of another object it has energy. If we restrict our study to mechanical energy, then we consider the changes in the state of motion of an object. There are different classifications of energy, usually named for the source of the force involved;
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submitted by kane (2199 m) on 30 Nov 2007 22:33:57 IST (4 comments 107 views)
What Are Electric Fields and Magnetic Fields? To understand electromagnetic waves, one must first understand electric and magnetic fields and how they interact. Electric fields make electric charges attract or repel each other. Similarly magnetic fields cause magnetic forces. There are two basic types of electric charges. They are positive and negative. In atoms, protons have positive charges and electrons have negative charges. Electric forces between the protons and electrons cause the electrons to orbit the nucleus. Like charges, such as two protons or two electrons, attract each other. Unlike charges, such as a proton and an electron, repel each other. These a
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submitted by kane (2199 m) on 29 Nov 2007 23:27:50 IST (0 comments 93 views)
Forces Forces One of the basic features in physics is the occurrence of forces that keep matter together. There are for example, the forces that keep the cells together to build up the human body, and there is the gravitational force that keeps us on the ground and the moon in orbit around the earth. We can ourselves exert forces when we push something and, by engineering, get some of the energy content in oil to produce a force on the wheels of a car to move it. From the macroscopic point of view we can imagine many different kinds of forces, forces that act at impact but also forces that act over a distance such as the gravitational one. In physics, though, we
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submitted by kane (2199 m) on 21 Nov 2007 22:47:46 IST (16 comments 358 views)
