consider a book lying on a table. the weight of the book and the normal force by the table on the book are equal in magnitude and opposite in direction.how do u say it illustrates newton's third law apart frm the fact that the forces r equal in magnitude and opp. in direction?
133779
This is not Newtons third law. the two forces you mentioned does not form action reaction pair. they act on the same body. Newtons third law in this case is : action : force of gravity exerted by the earth on the book , reaction : force of gravity on earth by the book. and action : normal force on the book by the table , reaction : force exerted by the book on the table in the downward direction
527034
Here you go.\nNewton's second law of motion can be formally stated as follows:\n\nThe acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of the object.\nIn terms of an equation, the net force is equated to the product of the mass times the acceleration.\n\nFnet = m * a\nIn this entire discussion, the emphasis has been on the "net force." The acceleration is directly proportional to the "net force;" the "net force" equals mass times acceleration; the acceleration in the same direction as the "net force;" an acceleration is produced by a "net force." The NET FORCE. It is important to remember this distinction. Do not use the value of merely "any 'ole force" in the above equation; it is the net force which is related to acceleration. As discussed in an earlier lesson, the net force is the vector sum of all the forces. If all the individual forces acting upon an object are known, then the net force can be determined. If necessary, review this principle by returning to the practice questions in Lesson 2.\n\n\nThe above equation also indicates that a unit of force is equal to a unit of mass times a unit of acceleration. By substituting standard metric units for force, mass, and acceleration into the above equation, the following unit equivalency can be written.\n\n\nThe definition of the standard metric unit of force is stated by the above equation. One Newton is defined as the amount of force required to give a 1-kg mass an acceleration of 1 m/s/s.\n\n\nThe Fnet = m a equation can also be used as a "recipe" for algebraic problem-solving. The table below can be filled by substituting into the equation and solving for the unknown quantity. Try it yourself and then use the "pop-up menus" to view the answers.\n\n\n Net Force\n(N) Mass \n(kg) Acceleration\n(m/s/s) \n1. 10 2  Depress mouse.a = 5 m/s/sa = F/ma = 10 N/2 kga = 5 m/s/s \n2. 20 2  Depress mouse.a = 10 m/s/sa = F/ma = 20 N/2 kga = 10 m/s/s \n3. 20 4  Depress mouse.a = 5 m/s/sa = F/ma = 20 N/4 kga = 5 m/s/s \n4.  Depress mouse.F = 10 NF = m aF = 2 kg x 5 m/s/sF = 10 N 2 5 \n5. 10  Depress mouse.m = 1 kgm = F/am = 10 N/10 m/s/sm = 1 kg 10 \n\n\nThe numerical information in the table above demonstrates some important qualitative relationships between force, mass, and acceleration. Comparing the values in rows 1 and 2, it can be seen that a doubling of the net force results in a doubling of the acceleration (if mass is held constant). Similarly, comparing the values in rows 2 and 4 demonstrates that a "halving" of the net force results in a "halving" of the acceleration (if mass is held constant). Acceleration is directly proportional to net force.\n\nFurthermore, the qualitative relationship between mass and acceleration can be seen by a comparison of the numerical values in the above table. Observe from rows 2 and 3 that a doubling of the mass results in a "halving" of the acceleration (if force is held constant). And similarly, rows 4 and 5 show that a "halving" of the mass results in a doubling of the acceleration (if force is held constant). Acceleration is inversely proportional to mass.\n\nThe analysis of the table data illustrates that an equation such as Fnet = m*a can be a guide to thinking about how a variation in one quantity might effect another quantity. Whatever alteration is made of the net force, the same change will occur with the acceleration. Double, triple or quadruple the net force, and the acceleration will do the same. On the other hand, whatever alteration is made of the mass, the opposite or inverse change will occur with the acceleration. Double, triple or quadruple the mass, and the acceleration will be one-half, one-third or one-fourth its original value.\n\n \n\nAs stated above, the dire
187205
Yes, that is Newton's first law of motion.  Newton's discovery may seem like a no-brainer to you or I, but at that time many people believed that an object fell to the ground because it was attracted to the earth.  His research opened up many new theories and formulas in the field of physics like work, energy, power, momemtum, and acceleration.\n\n#2 - "The acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of the object".  Basically force is equal to mass times acceleration.  F=ma\n\n#3 - "For every action, there is an equal and opposite reaction."  This means when you are leaning against a wall, you're applying 60kg of force against the wall and the wall is applying 60kg of force against you.  Action = Reaction.  When this equation doesn't balance out, something will usually break.
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NL2: F=ma\nFirst, Imagine a billiard/pool table with a ball on it that is at rest.  If you hit the ball with a stick, the ball will accelerate from the state of rest.  If you hit the ball harder, it will accelerate faster.  (from the formula, if you increase the "F"orce, the "a"ccelleration will also increase)\nNL3: F1=F2 (law of reciprocal actions)\nhttp://en.wikipedia.org/wiki/Newton's_laws_of_motion#Newton.27s_third_law:_law_of_reciprocal_actions\nif you hit a wall with your fist, not only the wall will get a hit from your fist, but also your fist will be hit by the wall (you may have some pain as a result)
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A body in motion stays at that same velocity unless acted on by an outside force (Newton's laws of motion). So the sum of the forces acting on the book is zero since the velocity is constant. Since you are applying a one newton force in the horizontal direction, and friction is the only other force acting on it in the horizontal direction, the force due to friction must be one newton in a direction opposite to the force you are applying.
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Silly...  The point your instructor is making is that barring any impeding object (air) in the horizontal(to the ground) velocity vector will remain the same (First Law of Motion).  Of course his use of never is inappropriate.  Any thrown object will eventually fall, go into orbit, or escape earth's gravity and fly into space.  At which point the object might encounter another impeding object...\nI recommend that you suggest to your instructor that he reword the question. (Forget trying to get the point).  Explain to him that Newton's First Law states "An object at rest tends to stay in rest and an object in motion tends to stay in motion in a straight line at constant speed unless acted upon by an outside force."...  Notice Newton himself refrains from the use of NEVER and uses the unless clause.  Explain to the instructor that you were using the UNLESS in the 1st Law.  That is to say he did not tell you to ignore gravity or any other impeding objects.  So, tell the instructor that you now understand what he was asking BUT s/he would be better off either taking out the NEVER (which Newton would not have used) with "until it hits the ground."\n\nAddition:\nGiven the Q as a true/false statement and understnading that the question is asking about Newton's First Law and knowing that even Newton says "nisi quatenus a viribus impressis cogitur statum illum mutare." which means "unless acted upon by an external and unbalanced force."  I would say FALSE! \n(The word "never" should not have been used).
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For these problems, it would be helpful to draw a free-body diagram to represent all the forces on this problem.  Here you have 4:\n\n1) Weight in the vertical direction going down, let's denote it W\n2) Force, moving in the x-direction, denote it F_1\n3) frictional force, moving opposite of Force, denote it F_2\n4) Normal force, perpendicular place of contact (opposite direction of W), denote it N\n\nNow use Newton's 2nd law to write equations in each direction:\n\ny-direction: \nN - W =0 (because the block does not move in the y-direction).  Therefore:\n\nN = W, where W = m*g\n\nx-direction:\nF_1 - F_2 = 0 [because the block is just about to move when F_1 is applied].  Therefore:\n\nF_1 = F_2, where F_2 = u*N\n\nMaking the necessary substitutions for F_1 and N, you get:\n\n30 = u*(4.4)(9.8).  Solving for u, you get --------->\n\nu = 0.7\n\n--------\n\nHope this helps
471495
its newtons first law, (objects in rest stay at rest unless a force is acted upon it which causes acceleration) and objects in motion stays in motion\n\naka intertia keeps the smaller peices moving in the same direction
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Although no theory is "right"  Newton is not "wrong" in the sense you probably mean it.  As I understand your question (you would do well to apply yourself to learning to write Engish as well as understanding physics), the table provides a reaction force up to its capability and then breaks.  The mass placed on the table then falls and the "reaction" is provided in its downward acceleration (F=ma) until it meets the floor after which the floor (hopefully) will provide the reaction needed to restrain the mass from further fall.  It is therefore the table and not Newton which is faulted.\n\nRegards,\n\nBramble.
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Because of the gravitational force the apple should go down. But it is not going down. Therefore we infer that there must be an upward force equal to the gravitational force.\n\nThe apple is exerting a force on the table. If we call it as action,then as per Newton's third law there must be an equal but opposite force ( reaction) on the apple by the table. This we call it as normal reaction force.\n\nTherefore there are two forces acting on the apple. \n\n1. The gravitational force acting down ward.\n2. The normal force given by the table on the apple.\n\nThese two forces need not be equal in magnitude.\n\nBut since the apple is at rest we infer that these two forces are equal and opposite and hence the net force on the apple is zero.\n\nImagine that the table top is made of thin paper. Then the paper will depress down and due to elasticity the paper tries to regain its original shape and hence gives an upward force. this force is the normal reaction.  The motion of the apple depends on the net force on the apple.
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haha, k  Draw a picture and draw a free-body diagram.\n\nI don't feel like busting out a paper/pencil  so I'll try it in my mind\n\nF(sub g) cos Theta  =  Mg cos(20 degrees)\n\nbecause the Normal force is equal to the y-component of gravity.\n\nTwo similar triangles, the incline and one which has the Force of gravity straight down, and the y compentn equal opposite of the normal force, and X component equal opposite to F\n\n\nlots of physics i'm skipping in my explanation tho
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it is a problem of moment of force.\njust calculate the sum of all clockwise moments and all anti-clockwise moments about the end of the tray.\n(moment of force = force * perpendicular distance of the force from the line of rotation)\nNow, for equilibrium, the sum total of anticlockwise moments is equal to the sum total of clockwise moments. Just give different names(symbols) for the different forces and then try this method. You will be able to get the answer if you are reading at class IX or above.
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The first law of Newton is, “an object is at rest or in uniform motion till a force acts on it”\n\nHence first law tells us what a force is.\n\nA force is one which changes the state of rest or state of uniform speed.\n\nAll the three laws of motion are implicated in the given example.\n\nFirst of all let us assume that the cart with the blocks is moving toward the solid barrier with a constant speed.\n\nThough both the cart and blocks are moving, the blocks are rest with respect to the cart and vice versa.\n\nThe static frictional force between the blocks and cart is preventing the relative motion between the two.\n\nNewton’s first law explains this. \n\nIf there is no frictional force between the two, then there will be relative motion between the two.\n\n Now consider the motion of the two together. Both are moving toward the barrier with constant speed.\n\nThus both will be in a state of constant speed till a force acts on them.\n\n“The cart hits the barrier” means, “The cart exerts a force on the barrier”.\nBy Newton’s third law the barrier exerts an equal and opposite force.\n\nWe are not bothered about what happens to the barrier when the cart exerts a force on the barrier but we are concerned about the reaction force- that is the force exerted on the cart by the barrier.\n\nThe cart comes to rest because of this force. By Newton’s first law the state of motion of the cart is changed to state of rest. \n\nWhen we consider the motion of the block on the cart, initially before the collision of the cart with the barrier, there was no relative motion between the two.\n\nWhen the cart strikes the wall, the speed of the cart is reduced where as the speed of the block is still in the forward motion (toward the barrier).\n\nThere fore, the blocks will move forward toward the barrier. \n\nIf we assume that there is no friction, then the blocks will move forward and hit some portion on the cart and hence their speed is reduced and increased in the opposite direction and they do fell off the cart. This is also due to the external force and is as per Newton’s first law of motion.\n\nIf we take into account the action of force of friction, the situation becomes some what hard to explain in a simple manner.
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Draw a board.  Make an upward force at one end equal to , say, 5 N.  Draw a downward force at the other end that is also equal to 5 N.  The two forces are oppositely directed and equal in magnitude, so their sum is zero.  But the torque on the board about any point is not equal to zero.
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It derives from one of Newton's Laws. In the simplest terms - when you exert force on an object, that object will move in a direction and distance exactly equal and opposite to the force you applied. But, the saying as we use it goes beyond this physical explanation. I think it refers to the fact that all your actions have consequences and that therefore you should consider things carefully before you act. Things we do affect other people and those effects can change the world.
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Use free body diagram to balance the forces and u can derive the equation of motion \nIf u want i can give u full derivation.\n"::
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You mean Newton's 2nd law of motion, don’t you?\n\nForce = mass * acceleration\n\nI like this law, a lot, actually.\nIt may not seem very intuitive at first to someone trying to learn it, but with practice, you'll come to understand.\n\nThe basic concept is that a [net] force applied to an object causes it to accelerate.  When you push on something, it moves.  They key work being a "net" force.  If there is no net force (i.e. F = 0), there is no acceleration.\nThe force the chair is exerting on you, called the "Normal" force is necessary because while you are sitting in the chair are you falling towards the ground?  No, of course not.\n\nWe all know that Earth (gravity) exerts a force on you in the downward direction, called "Weight".  Without a balancing force, you would continue to accelerate downward.  If the chair did not exert a normal force back upward to cancel weight, there would be a net force acting upon you in the downward direction which would cause you to accelerate downward.\n\nA similar case is true for other objects, like when you push on a wall.  In this case, it is not gravity which exerts the force, you are doing it.  In order to keep the wall from accelerating when you push on it, the wall must exert a force back which is "normal" to its surface.  Eventually, however, the wall will not be able to provide ample normal force to counter your push and parts of the wall will begin to accelerate as the wall breaks.