what force holds an object in circualr orbit?
475251
If I remember correctly from my high-school physics class, it's a combination of gravity and one of Newton's laws of motion - the one that says "an object in motion stays in motion unless acted on by an outside force." So that force keeps it moving around and gravity keeps it from just flying off into space.
512623
I will state this here, in yet another question: THERE IS NO SUCH THING AS CENTRFUGAL FORCE!! Look it up in a basic physics textbook like Giancoli or Serway. Or even do a google search. You have to understand what reference frame you're talking about. The fact that your body tends to want to move to the outside of the curve when your car goes around in a circle has nothing to do with anything other than the fact that your body wants to keep going along in a straight line (conservation of momentum), but the car gets in front of it at every turn (semi pun intended). What is actually happening is that the car is an accelerating reference frame.\n\nAs for the moon/earth question... imagine a man 6' tall throws a tennis ball horizonatally with respect to the earth's surface. The ball will go forward a certain distance (because of it's velocity tangential to the earth's surface) as it falls the ~6' to the ground (because gravity pulls it down). The faster he throws the ball (horizontally), the further it will go before it hits the ground. If he throws it fast enough then the amount that the ball travels forward and the amount that it drops towards the earth's surface can match the curvature of the earth, and the ball will orbit the planet (neglecting air resistance, as we physicists always do) and come around and bonk the thrower in the back of the head. The moon is just a much larger tennis ball, thrown by a much larger man.\n\nYour eqn. is correct, but it only describes the force acting upon the moon. It is not the equation of motion, which detirmines what actually happens to the moon. The equation of motion is:\n\nF = m * a  (F = force, m = mass of moon, a = acceleration of moon around earth)\n\nIn the case of the circular motion of the moon around the earth, "a" is defined by:\n\na = (v^2)/r (where v is the magnitude of the velocity of the moon and r is the center-to-center distance from the earth to the moon)\n\nPlugging one into the other you get:\n\nG * M * m/r^2 = m * (v^2)/r (where M is the earth's mass)\n--> G * M/r = v^2\n\nSo, as long as the tangential velocity, v = sqrt(G * M/r), the moon falls just enough towards the earth as it travels just enough tangentially second by second, that it continues to orbit around the earth. (Note: there is NO CENTRIFUGAL FORCE anywhere in any of these eqns.!!)
596583
Mass. I think.Depending on how strong the gravity is your mass changes.
1037132
Well, you need to take more than one law into account.  There's also the law of inertia; that an object in motion tends to stay in motion along a straight line unless another force acts on it.  In the earth's case, that other force is the sun's gravity.  As a result of the earth's own intrinsic motion and the sun's gravitational pull, the earth continues to orbit around the sun (though the sun is winning out, veeeerrrry slowly).  To disturb that equilibrium, you'd need a very large mass and/or a very high speed to overcome earth's inertia enough to knock it out of orbit.  While the impact of asteroids do have *some* effect, because asteroids come from every direction their cumulative effect evens out.  \n\nAn analogy would be walking outside on a windy day.  Normally, if there's no wind or an occasional breeze, it doesn't affect you much.  But if there's a strong wind coming from one direction then you get pushed by it, and a really strong gust can knock you over.
539114
This is basically Newton's law of inertia in action. All objects in motion will stay in motion and all objects at rest will stay at rest until an outside force is introduced. The most common outside force on Earth is friction. There is friction between the tablecloth and the objects on top of it. That's why if you pull the cloth slowly, the objects slide off, but when you pull the cloth quickly, you reduce the friction and the inertia of the objects makes them stay where they are.
818860
I'm not going to give you the complete answer because you'll learn more by working through it yourself, but I'll give a few pointers.\n\nAny object travelling in a circle at a constant speed has a centripital acceleration that can be calculated from the velocity and the radius of the circle.\n\nNewton tells us that F[net] = ma, so the object must be experiencing a net centripetal force equal to its mass multiplied by its centripetal acceleration.\n\nWhere does this force come from?  In your problem, it sounds as though the only force that could be pulling the box toward the center of the circle (the centripetal force) is the friction between the box and the bed of the truck.  So, when you add up all the (horizontal) forces to get the net force, the olny one is going to be friction.  F[net] = F[friction] \n\nNow all you need to do set F[friction]  equal to the F[net] that you calculated above (remember that F[net] was equal to your centripetal force), and solve for the coefficient of friction (your textbook shold have the formula for static friction, which will include the coefficient of static friction).\n\nGood luck!
818764
If the objects have designated capture/handling points, the EE must be able to find them or be guided to them, and engage them.\nIf operating in a gravitational environment (such as on earth) consider picking objects up fork-lift style rather than by grasping; then the only forces will be gravitational (plus any acceleration applied by the EE).\nForce sensing and limiting (via feedback) may be needed; grasping, gravitational and acceleration forces should be taken into account.\nEE contact points/areas may need to be padded to distribute forces over a wide area, and/or the contacting limbs be made highly compliant.\nConsider a snare arrangement for initial capture.\nThe refs. contain some elements of gentle handling used on the Space Shuttle's robotic arm (RMS).\nIf allowed, the objects you intend to lift should be designed with capture points such as the "grapple fixture" on RMS-handled payloads.
676531
Forces of vander wall I will tell you this in most simple way because that is what I think that you want to know.\nVander Wall forces ( they are forces not bonds, remember always)\nWell those forces are determined by a balance of attraction and repulsion charges between nucleus and atoms.\n\n  One example is this as you know the solar system has planets, they  rotate around the sun and keep distance each another. well\n there are two forces called centrifuge and centripetal, those forces are responsible for the planets to stay in a stable way to rotate without go out of their orbits.\n is the same with the vander wall forces but of course in a molecular level.\n HOW DO WE KNOW ABOUT IT?\nwell those forces have the name of the scientific who discover that behavior in the atomic and molecular world.
263427
gravitation, electromagnetic force, nuclear force
242244
The theory behind orbiting is to get the centrifugal force to equal the force of gravity. Without centrifugal force the object would fall. Without gravity the object would go in a straight line. The faster the object of course the greater the centrifugal force. The higher the object is the less the gravity, geosynchronous orbit is at 35,786 kilometers.\n\nSo in order to orbit you need gravity. Like the earth hasn't escaped the suns gravity. It is just a a distance and speed where the centrifugal equals the force created by the gravitional pull. Same with the moon orbiting the earth.
854417
The four fundamental forces are:\n\n1-Gravitational Force\n2-Electromagnetic Force (the force between charged particles - the photon is the mediator of this force)\n3-Strong (nuclear) Force - keeps nuclei bound together\n4-Weak Force (responsible for Beta decay of the nucleus)
734596
A force at its most simplistic is a push or a pull. According to Newton's laws of motion, when something is at rest or travelling at constant velocity, there is NO force acting on it. \n\nNewton's second law states that Force = mass x acceleration which means that a force causes a _change_ in velocity (acceleration). So for continuing motion, there is only a force when there is acceleration.
1094061
Earth is revolving in orbit, held in place by the Sun's gravitational pull
433264
Objects orbit one another because they have a curved trajectory that results from the vector addition of their momentum (in the direction of travel, tangential to the orbit) and the gravitational attraction to the other object (normal to the orbit).\n\nThis vector is constantly changing in direction (but not to any significant degree in magnitude) because of the object's motion, but it always keeps the satellite's acceleration pointed towards the object is it orbiting, resulting in smooth, roughly circular motion.
442199
towards the moon or towards the sun?\n\nand i think its centripetal force. (or however you spell it)\ngood luck.
279317
gravity.\n\nany shape of mass that is not spherical is gravitationally unstable
660806
centripetal force and centrifugal force\ncentripetal force and centrifugal force, action-reaction force pair associated with circular motion. According to Newton's first law of motion, a moving body travels along a straight path with constant speed (i.e., has constant velocity) unless it is acted on by an outside force. For circular motion to occur there must be a constant force acting on a body, pushing it toward the center of the circular path. This force is the centripetal (“center-seeking”) force. For a planet orbiting the sun, the force is gravitational; for an object twirled on a string, the force is mechanical; for an electron orbiting an atom, it is electrical. The magnitude F of the centripetal force is equal to the mass m of the body times its velocity squared v 2 divided by the radius r of its path: F=mv2/r. According to Newton's third law of motion, for every action there is an equal and opposite reaction. The centripetal force, the action, is balanced by a reaction force, the centrifugal (“center-fleeing”) force. The two forces are equal in magnitude and opposite in direction. The centrifugal force does not act on the body in motion; the only force acting on the body in motion is the centripetal force. The centrifugal force acts on the source of the centripetal force to displace it radially from the center of the path. Thus, in twirling a mass on a string, the centripetal force transmitted by the string pulls in on the mass to keep it in its circular path, while the centrifugal force transmitted by the string pulls outward on its point of attachment at the center of the path. The centrifugal force is often mistakenly thought to cause a body to fly out of its circular path when it is released; rather, it is the removal of the centripetal force that allows the body to travel in a straight line as required by Newton's first law. If there were in fact a force acting to force the body out of its circular path, its path when released would not be the straight tangential course that is always observed.