What is the work done by gravity?
824936
a) You have to draw gravity as a straight line down. Then you have to realize that gravity does no work if the block was on a horizontal surface. Work done by gravity is alway M*G*H.  The mass is 4.8 kg and the gravity is 9.81 m/s^2 .  The height will be sin (30) = H/2.  the sin (30 degrees) is 0.5 so .5=H/2.  the height will be .5/2 = .25 m.\n\nsoo you will have 4.8*9.81*0.25\n\nb) the work done by the frictional force will always be the frictional force times the distance.  The frictional force is going to be the normal force times Uk.  The normal force has components to it, so its going to be sin(30)*g*m.  The you need to multiply that by the friction coefficient and then by the distance traveled.  You will have 2*0.436*sin(30)*4.8*9.8\n\nc.  The work done by the normal force is just going to be cos(30) (i think) times 2 ( the distance traveled) times 9.81 (gravity) times 4.8 (the mass)
936812
Uhhh..\nWork = Force * Distance..\nEnergy = Work
1179191
Work done by the force 2.34 N is, ‘force x distance through which the force is moved’.\n\nTherefore, it is = 2.34 N x 1.41m = 3.2994 joule.\n\nWork done by the frictional force 0.55 N is, ‘force x distance through which the force is moved’.\n\nTherefore, it is = 0.55 N x 1.41m = 0.7755 joule.\n\nThe last question is vague. \n\nThe total work is the work done by the force 2.34 N and it is equal to 3.2994 joule. \n\nOut of this total work a part (3.2994 -0.7755 = 2.5239) joule is used to accelerate the book and 0.7755 joule is dissipated as heat energy.
987930
No energy source? What source of energy is needed? And the simple presence of mass causes gravitons. And these gravitons interact with one another. And proof, you need proof that gravity works? Dude go jump off of a building and see what happens!
1066612
Work = force x distance\n\nforce = mass x force of gravity\n\nso F=110 kg x 9.8 m/s = 1078 kg m/s^2 or 1078 Newtons\n\nWork = 1078 N x 12 m = 12936 kg m^2/s^2 or 12936 Joules
1144696
gravity and air resistance.
67988
The first answer is correct.  Energy.  Energy is defined as force applied through a distance.  This specific type of energy is known as kinetic energy (energy of motion).  Energy is measured in joules, or J.  E = F x D, so if you applied 50 Newtons and the object moved 1 metre, you would have expended 50 joules.
715637
Work and energy always involves comparing energy before and after\n\nKE[before] + GPE [before] = KE[after]+GPE[after]\n\n(KE=kinetic energy; GPE=gravitational potential energy)\n\nor more advanced situtations include EPE (elastic potential energy) but don't worry about this.\n\nYou should know that KE = 1/2mv^2 and that GPE=mgh\n\nUsing the inclination and angle should get you the height. \n\nUsing F=μR and F=ma and manipulation, involving replacing a with speed, should get you the answer.\n\nAlways draw a diagram and resolve horizontally and vertically\n\nHope this helps
1791
Gravity attracts an object with mass towards the center of the earth.  You must do work, expending your own energy, to overcome gravity and raise a weight.  The weight now has potential energy equal to the weight times the distance raised.  If you raised a 100 Lb weight one foot, you did 100 ft-Lbs of work on the weight and the weight now has 100ft-Lbs of Potential Energy that can be used to do work, such as lift another weight on the other end of a seesaw.  All of the energy discussed derives from the earth's gravitational field which has been converted to mechanical energy.  You could perform the same task on the moon except the amount of work and potential energy would be far less because the moon has less gravity.  Also a pound weight on earth would weigh far less on the moon and scientists would usually use units of mass which is constant on the moon and earth to perform calculations.
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.
80396
Yeah i know:\nDo this:\n\na.)Find the work done by the applied force.\n\nb.)Find the work done by friction\n\nc.)Find the work done by gravity\n\nd.)Find the work done by the normal force.\n\ne.) IF the object starts at rest, how fast is it going after the 5.0m.\n\nhope this helped\n-----------\n\nNO I WILL NOT HLEP YOU. DO YOUR OWN WORK! your asking someone to do your work for you.
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
650418
Work is when you exert a force and an object moves in the direction of the force.  Power is the rate at which work is done.  And please don't copy this answer for homework or something like that because that would be cheating.
868908
work done = force x displacement x cos(A)\n\nthe angle (A) is defined as the angle between the force and the displacement vectors
980630
Gravity is a field force created by the presence of mass in space-time. Consequently, two masses separated by some distance, r, will always have the potential to do work in the process of getting closer together. That is, the same amount of energy is required to separate the masses as is released by bringing them closer together. \n\nSo, you can get energy from the system as long as there is a distance between the two masses. However, in obtaining that "free energy," you've brought the masses closer together. If you want to restore the system to its original state, you'll have to supply the same amount of energy you've just extracted. This leaves you zero net energy gain.\n\nImagine a big lake at the edge of a cliff, and imagine that there is a waterfall over the cliff at one place. Now imagine that we put a paddle wheel at its base to catch the falling water. This will cause the wheel to spin, and we can hook this spinning wheel up to a generator to get free power. Sounds great, right?\n\nIt is...until the lake is drained. Once the lake is gone, there's no water to supply our wheel and we can't get anymore power from the system. What you're suggesting is that we should divert some of the power we've extracted from the system to pump water back up into the lake so that it can fall again, turn our paddle, and give us an infinite supply of energy.\n\nThe problem is, the energy required for us to put the water back is actually greater than the energy that we've gained in the first place. So in reality, we're not gaining anything but are instead constantly losing energy.\n\nThe same goes for buoyancy. In fact, buoyancy is a manifestation of gravity; the buoyant force on a mass in a liquid is equal to the weight of the fluid it has displaced. Again, energy is given off by letting a buoyant object rise, but the same amount is then required to bring it back to where it started. The whole cycle does not produce work (in fact, it requires we put more energy in than we get out).
791910
The work done on an object by a force is the product of the component of the force in the direction of motion and the distance the object moves. The component of the force in the x direction is simply the magnitude of the force times the cosine of the angle. Thus:\n\nW = 100 N * cos 40° * 20.0 m ≈ 1530 J (to 3 significant digits)\n\nEdit: I don't know whether your teacher is complaining about the units or the numbers. A joule IS a newton·meter, so both units are correct. As for the number, I'd say someone made a typo when compiling the answer key. It happens a lot. Ask her to recompute it herself.
922769
Okay so start off by looking at the definition of work.\n\n"Work is a force exerted on an object that causes it to have a displacement in the same direction.\n\nW = Fd\n\nW = work (Joules), F = force (Newtons), d = displacement (metres)\n\nBy definition, 1 J of work is done by applying 1 N of force to move an object 1 m.\n\n    * Work has no direction, so it is a scalar quantity.\n    * Also, the direction of motion must be in the same direction (parallel) as the direction of the force, otherwise no work is being done."1\n\nSo there are two things you could look at here.\n\nW = Fd\n\nHow much displacement is there in one full cycle of something moving in a circle?  Displacement is the change in position so look at the position at the beginning and ending of the cycle.  There is no change in position so d=0 which gives\n\nW=F(0)\nW=0.\n\nNo work done.\n\nAnother thing you have to look at is "Also, the direction of motion must be in the same direction (parallel) as the direction of the force, otherwise no work is being done"\n\nIn uniform circular motion the movement of the object at any point in time is tangential to the circle while the force is always directly towards the centre of the circle so the movement and force are never in the same direction.  The definition of work demands that they be in the same direction for any work to have been done and, since they are not, no work has been done.\n\nShort answer: c. 0 J