What is the difference between friction and gravity?
609398
FRICTION is the energy generated when two bodies have some physical interaction with each other. \n\nGRAVITY is the force of a mass which pulls an object towards its center.
883514
There are 2 types of friction: kinetic and static\nKinetic friction slows a sliding object to a stop.\nStatic friction prevents a stationary object from moving. It is usually much stronger than kenitic friction. (That's why it is tough to get a heavy, stationary cardboard box to slide on the carpet, but once it's moving, it becomes easier)\n\nWith your automobile example, the tires on the car roll on the ground. It's important to note that they roll... not slide, because sliding object experience kinetic friction forces, while rolling objects experience static friction forces. (This is why you get a carpet burn if you slide on the carpet, but not if you roll).\nStatic friction prevents the tire from "Sliding" on the road, even though the axle of the car is forcing it to rotate. The tire applies a "horizonal" force on the road, attempting to slide (and squeel), but the road applies an equal and opposite static frictional force. The result is a "roll".\n\nIf for some reason, the you slam on the breaks and the breaking force applied to the tire exceeds the maximum static friction force between the road and the tire, the tire will slide (skid). The resulting kentic frictional force stopping the car is much smaller than the previous static frictional force stopping the car. As a result, skidding cars slow down less rapidly than reglar breaking cars. This is why anti-lock breaks were invented - to keep cars from skidding in a stop.\n\nI really hope this helps. Tried to keep it short and sweet.
710706
Gravity, friction and centrifigul.  Don't forget various applications of force = leverage, pulleys.
833832
Kinetic friction is equal to the Frictional force divided by the Normal force  (k = Ff / Fn)\n\nStarting at the standard equation F = ma , we need to modify this because there is some friction involved.\n\nThe two forces are our Applied force (Fa) and our Friction force (Ff).  Because Ff is acting in the opposite direction, it will be negative.  Therefore we have Fa - Ff = ma.\n\nThe key to this question is to know that because there is a constant velocity, the acceleration is equal to 0.  \n\nSo Fa - Ff = 0.  However is we re-arrange this, we have Fa = Ff\n\nThis means that the Applied force (Fa) is equal to the Frictional force (Ff).\n\nAlso, the Normal force (Fn) is equal to the Force of gravity (Fg) because we are on a level floor with no vertical displacement.  Remember though that Fg = mg.  g is yor gravitational constant.  Because there is no movement in the vertical direction, it will not be negative.  \n\nSo to solve this question, \n\nk = Ff / Fn\nk = Fa / Fg  (because like I mentioned above Ff = Fa and Fn = Fg)\n\nNow work with the number that you have.  We don't have Fg but we can solve for it using the given mass (12kg) and the constant g = 9.8\n\nk = Fa / mg\nk = 30 / (12)(9.8)\nk = 0.2551020....\n\nNoting your significant digits of 3 decimal places...\n\nThe coefficient of friction is 2.55 x 10 ^ -1\n\nHope that helps you out a little bit.
198734
The force of friction is dependent on two things, the Normal force between the "object" and the "surface" and the coefficient of friction between the two.\n\nThe normal force on a level surface is equal the weight of the object.  You are given the mass, from this, you can easily calculate the force of weight (and this F_n).\n\nYou are given the coefficient of friction, greek letter mu.\n\nThe force of friction can be found as,\nF_f = F_n * mu\n\nThe force of friction is always in the direction opposite that of the motion.  So if your traveling "forward", the frictional force is pointed "backward".\nWhat are the two components in the formula that affect the magnitude of the frictional force?  Just the normal force (which is dependent on mass and gravity) and the coefficient of friction.  For all intensive purposes, mu is constant, as is the mass and gravity of the object.  Therefore, the force of friction is constant.\n\nYou are given in initial velocity.  You are trying to find how far (change in distance) the car will travel while this constant force is being exerted on it before the car comes to a stop.\nThere are several ways this could be found.  I think the energy method would be the easiest, but I will cover the kinematic method as well....\nThe car has some initial kinetic energy when the problem starts out.  KE = 1/2 mv^2.  After the car comes to a stop, the car has zero KE...therefore some work had to be done on the system to change the energy (we assume a level road).  The change in KE equals the work done.  Work is also equal to the product of the force applied over the distancd applied.\nW = F * d\nSince the frictional force is what is causing this change in energy (which we know, it was calculated earlier), and we also know the change in KE, we can simply solve for the distance, d.\n\nThere is also another possible solution.\nWe know that the frictional force will cause an acceleration.\nF = m*a\nWe know that an acceleration will cause a change in velocity.  We know ,\nv_f^2 = v_i^2 + 2ad\nwhere v is velocity (i is initial, f is final), a is acceration, and d is distance.  Simple solve for d.
1152166
a:  specific gravity is the ratio a subtances density compared to water or other reference material.  Density is weight per unit volume.\n\nb: mass is amount of substance, weight is the mass as it is affected by gravity.
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Gravity is a condition of the space-time continuum which is associated with mass.  Every object which has a mass will have a gravitational attraction to any other close object with a mass.\n\nThe planet Earth has a mass, and therefore has a "gravity."
1016707
there is friction in space as said before but it is also because there is matter in space, just not very much, and eventually it would cause the object to stpo spinning
443615
Friction is hte result of Newton's law which says that to any action there is an opposite and equal reaction. Friction is the result of the interlocking of uneven parts of two substances. So you can understand what would happen if there was no reaction to an action. There would be no football, hockey, swimming, baseball, and all other sports.
112179
Gravity is a force of attraction that acts between bodies that have mass. It is a physical phenomenon of fundamental importance, profoundly affecting the workings of the world around us and the universe beyond. Most familiarly, it is the gravitational attraction of the earth that endows objects with weight and causes them to fall to the ground when dropped. In fact, gravity is also the reason for the very existence of the earth, the sun and other celestial bodies; without it matter would not have coalesced into these bodies and life as we know it would not exist. Gravity is also responsible for keeping the earth and the other planets in their orbits around the sun, the moon in its orbit around the earth, for the tides, and for various other natural phenomena that we observe.\n\nIn common usage "gravity" and "gravitation" are either used interchangeably, or the distinction is sometimes made that "gravity" is specifically the attractive force of the earth, while "gravitation" is the general property of mutual attraction between bodies of matter. In technical usage, "gravitation" is the tendency of bodies to accelerate towards one another, and "gravity" is the force that some theories use to explain this acceleration.\n\nGravity was rather poorly understood until Isaac Newton formulated his law of gravitation in the 17th century. Newton's theory is still widely used for many practical purposes, though for more advanced work it has been supplanted by Einstein's general relativity. While a great deal is now known about the properties of gravity, the ultimate cause of the gravitational force remains an open question and gravity remains an important topic of scientific research.\n\nContents [hide]\n1 Overview of the history of gravitational theory \n2 The Earth's gravity \n2.1 Comparative gravities of the Earth, Sun, Moon and planets \n3 Mathematical equations for a falling body \n3.1 Gravitational potential \n3.2 Acceleration relative to the rotating Earth \n4 Gravity and astronomy \n4.1 Self-gravitating system \n5 Practical uses of gravity \n6 Newton's law of universal gravitation \n6.1 Acceleration due to gravity \n6.2 Bodies with spatial extent \n6.3 Vector form \n6.4 Gravitational field \n7 Problems with Newton's theory \n7.1 Theoretical concerns \n7.2 Disagreement with observation \n7.3 Newton's reservations \n8 Einstein's theory of gravitation \n8.1 Experimental tests \n9 Comparison with electromagnetic force \n10 Gravity and quantum mechanics \n11 Alternative theories \n11.1 Recent alternative theories \n11.2 Historical alternative theories \n12 Notes \n13 See also \n14 References \n15 External links \n \n\n\n[edit]\nOverview of the history of gravitational theory\nThe first mathematical formulation of gravity was Isaac Newton's law of universal gravitation, published in his 1687 work Principia Mathematica. Professor William Whewell of Cambridge University, author of History of the Inductive Sciences (1837) stated:\n\n"The law of gravitation is indisputably and incomparably the greatest scientific discovery ever made, whether we look at the advance which it involved, the extent of the truth disclosed, or the fundamental and satisfactory nature of this truth." [In A Treasury of Science ed. Harlow Shapley et al, Harper & Bros. NY: 1946] \nAlthough the law of universal gravitation was first clearly and rigorously formulated by Isaac Newton, the phenomenon was observed and recorded by others. Even Ptolemy (c. 100-178) had a vague conception of a force tending toward the center of the Earth which not only kept bodies upon its surface, but in some way upheld the order of the universe. Indian astronomer Brahmagupta (598-668), who followed a heliocentric solar system, was the first to recognize gravity as a force of attraction. He explained that "bodies fall towards the Earth as it is in the nature of the Earth to attract bodies
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Gravity is the force that holds everything down. Gravity also affects different people depending on their body mass. It you are taller, you have a greater gravitational pull on you which makes you weigh more.  The force of gravity is strongest when it is closest to the core of the Earth. The closest that we can get to the core of the Earth is sea level. So you would weigh more at sea level than you would on a top of the mountain. You would still have the same body mass, but just a different body weight. Mass is how much matter is in something, and weight is the measure of the gravitational pull on you. So that is how you can weigh a lot if you are taller. You're not fat, you just have a strong gravitational pull.
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You are confusing energy and gravitational force. The two are\nnot equivalent. The property of gravity is based upon the mass of an object, the more mass an object has, the more gravity it posesses. The amount of gravity an object has does not increase or decrease with time.
1117792
Let's make this simple: \n\nInertia and Momentum refer to Newton's 1st Law...Momentum tell us that an object in motion will stay in motion, and inertia tell us that an object at rest will stay at rest...both until acted upon by an unbalanced force.\n\nKinectic energy refers to the energy of moving objects.  (as opposed to potential energy, that refers to objects that are not moving, but that could move.)\n\nExamples:  \n\nInertia:  A pencil sitting on my desk will not move until something moves it.  This is a very comforting thought if you stop and think about it.\n\nMomentum:  If I'm riding my bike, I will continue to move until the force of gravity pushing down on me, and friction moving against the tires, and the wind blowing in my face all conspire to stop me.\n\nKinetic energy:  This is the sum total of all the energy spent keeping my bicycle moving...my legs pedaling, gravity pushing me down the hill, then subtract the forces acting against me.\n\nHey, it ain't rocket science...it's easy!
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They all involve friction, but I think you mean which has the most force due to friction, right? :-&#92;  If so, I believe the answer is that they are all the same.\n\nIn simple situations, the frictional force created by sliding two surfaces against eachother is given by:\n\nf = u * N\n\nWhere u (mu) is the frictional coefficient (an experimentally-determined constant) and N is the normal force, which is mg (mass times accelleration of gravity) if the surface isn't tilted.\n\nSo, assuming the frictional coefficient is the same for all sides of the book, there is no reason why changing the sides would make a difference.
21267
Gravity is the force of attraction between massive particles. Weight is determined by the mass of an object and its location in a gravitational field. While a great deal is known about the properties of gravity, the ultimate cause of the gravitational force remains an open question. General relativity is the most successful theory of gravitation to date. It postulates that mass and energy curve space-time, resulting in the phenomenon known as gravity.\n\nGravity is acceleration.  means that (if the mass is unvarying) there must be a force that causes a mass to accelerate. For a rocket ship, that is the rocket engine. For the earth, it is the compression of the mass between something on the surface of the earth and the earth's center of mass. The acceleration is in relation to spacetime in that the weight one feels is one's resistance to deviating from one's path in spacetime. The same holds true in the rocket ship except that a rocket engine supplies the force to accelerate an occupant from his spacetime path. There is no difference between the weight he feels because of gravity or the rocket.
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The force of friction always opposes the motion.  \n\nWhen a force is applied to a ball or wheel, it will start rolling, provided there is a resistive force preventing the wheel from simply sliding along the other surface. The force may be a torque applied to the axle of the wheel or a linear push or pull on the wheel. The resistance of static friction causes the rolling motion. If the wheel or tire has treads and the other surface is soft, then those treads provide extra friction known as traction.\n\nNote that the friction required to start rolling motion is not rolling friction, which is defined as the friction slowing down rolling motion.\n\nAccording to the law of conservation of energy, no energy should be lost due to friction. The kinetic energy lost is transformed primarily into heat and/or motion of other objects and fluids. An airplane will heat and accelerate the air as it passes. A submarine will do the same to the water. In some cases, the "other object" to be accelerated may be the Earth. A sliding hockey puck will come to rest due to friction both by changing its energy into heat and accelerating the Earth in its direction of travel (by an immeasurable amount)
544891
The formula is actually divided up into two cases:\nForce friction = Force Applied when Force Applied < mu Static x Force Normal (i.e. nothing'll move below this threshold)\nForce friction = mu dynamic x Force Normal otherwise.\n\nThere is no formula for the two mus; they are measured experimentally.