In classical mechanics, momentum (pl. momenta; SI unit kg m/s) is the product of the mass and velocity of an object. For more accurate measures of momentum, see the section "modern definitions of momentum" on this page.
In general, the momentum of an object can be conceptually thought of as how difficult it is to stop the object, as determined by multiplying two factors: its inertia (the resistance of an object to being accelerated) and its velocity. As such, it is a natural consequence of Newton's first and second laws of motion. Having a lower speed or having less mass (how we measure inertia) results in having less momentum.
Momentum is a conserved quantity, meaning that the total momentum of any closed system (one not affected by external forces, and whose internal forces are not dissipative in nature) cannot be changed.
The concept of momentum in classical mechanics was originated by a number of great thinkers and experimentalists. René Descartes referred to mass times velocity as the fundamental force of motion. Codi Kruse in his Two New Sciences used the term "impeto" (Italian), while Newton's Laws of Motion uses motus (Latin), which has been interpreted by subsequent scholars to mean momentum
2007-03-30 17:16:54
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answer #1
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answered by Anonymous
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Well, since I don't know your level, let me go down as low as possible for me and try to explain. The deficiency is mine, not yours, if you don't understand!
You know momentum is the product of mass and velocity. Since mass of a given object is constant, the higher the velocity the greater the momentum and when it is suddenly stopped, the greater the impact!
You also know that kinetic energy is 1/2 m.v^2. So, the higher the velocity of an object of mass m, the higher the energy and higher the momentum. Also remember that both energy and momentum are conserved. Energy gets converted into some other form. Momentum gets transferred from one body to another.
Try this simple experiment. Get a rubber ball, not very hard nor very soft, medium. Throw the ball against the ground or against a wall. Throw with different speeds and observe the impact on your palms when you try to catch it on rebound. With higher momentum, the impact on your palms will be higher. You will be observing something similar when you are running and suddenly run into a wall or another person. The faster you are running, the more will be the shock and impact.
If you are playing baseball, you will be able to relate immediately when you try to catch a powerful shot or just a simple throw. The palms need to absorb much more impact in the first case when the batter hits it. You wear gloves to absortb that excess momentum, you move your hands back to reduce the shock.
Finally visualise a small ball hitting the earth and a plane crashing into the ground or a 1000 kg bomb falling from a height. Why the destruction is so much more in the later cases? Due to the higher momentum which has to be absorbed by the earth and any people there.
Hope you got a better idea now than a few minutes earlier.
2007-03-31 04:24:02
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answer #2
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answered by Swamy 7
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The equation for this is p=mv
Really, it is just an object moving at a certain speed.
Objects in motion are said to have a momentum. This momentum is a vector. It has a size and a direction. The size of the momentum is equal to the mass of the object multiplied by the size of the object's velocity. The direction of the momentum is the same as the direction of the object's velocity.
Momentum is a conserved quantity in physics. This means that if you have several objects in a system, perhaps interacting with each other, but not being influenced by forces from outside of the system, then the total momentum of the system does not change over time. However, the separate momenta of each object within the system may change. One object might change momentum, say losing some momentum, as another object changes momentum in an opposite manner, picking up the momentum that was lost by the first.
2007-03-31 00:13:40
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answer #3
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answered by Imperator 3
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No one can explain that. You only can work with it fruitfully.
Second law of Newton rewritten is F x delta t = delta (mv)
Left you seen things that do no belong to the object, at the right side you see features of the body on which the force acts.
In relativistic mechanics momentum is more essential than mass, because total momentum has been conserved always, while mass and energy do not. Mass and energy are exchangeable: E = mc2.
Th
2007-03-31 04:54:58
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answer #4
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answered by Thermo 6
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Momentum is what keeps objects moving in a straight line in the absence of another force like friction.
An example of this is when you are riding down a street on your fast bicycle and your bicycle suddenly hits a car. You continue to fly over your bicycle handle bars at the same speed that your bike was going. That's momentum.
When a football player leaps into the air at the end zone, the player keeps going forward at the same speed despite the fact that he has no contact with the ground. That's momentum.
When a billiard ball hits another billiard ball straight on, the energy is transferred to the second ball. The first ball stops, the second ball continues at the same speed as the first ball because of the energy transfer. The momentum was transferred from one ball to the other.
2007-03-31 00:17:16
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answer #5
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answered by Skeptic 7
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Momentum is used in Newtons law, You know already about action and reaction. To measure the momentum of an object you have to take into account the initial force shape and angle travelling so its not easy to write about but did find a site for you http://en.wikipedia.org/wiki/Momentum#Modern_definitions_of_momentum
Hope it helps
2007-03-31 00:27:16
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answer #6
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answered by noblueloo 2
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relative to your fix position another object moving by has motion - that motion is momentum - technically both objects could be moving and not be in a fixed position. You can move - stare at an object that seems fixed -- looking out a car window - now envision that one object out the window is in a fixed position but the rest of the landscape is moving in your cars opposite position or perhaps moving further away perpendicular to you. Your brain says the land ain't moving - just your car and NOW you got this moving tree to deal with. At least that is what my daughter told me when she did a three point turn and some tree hit her rear bumper.
2007-03-31 00:17:12
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answer #7
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answered by Anonymous
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tell your teacher to stop being lazy and give the complete explanation of what hes talking about so his students can understand the lesson.
momentum is the energy applied to an object to keep it moving. The opposite would be resistance. Without resistance, an object in motion would stay in motion for ever.
2007-03-31 01:26:46
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answer #8
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answered by t2kmf 3
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Momentum is what a moving body has.
A body at rest has only weight.
If you want to lose weight, start moving and get momentum.
2007-03-31 00:44:03
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answer #9
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answered by gatorbait 7
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well, you probably already know this. but momentum is what you feel when you are coasting in a car or on a bike. Your wieght is pushing you forward
2007-03-31 00:13:09
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answer #10
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answered by czechoslovakian67 3
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