In physics, apparent weight is a property of objects that corresponds to how heavy an object appears to be. The apparent weight of an object will differ from the ordinary weight of an object whenever the force of gravity acting on the object is not balanced by an equal but opposite contact force. By definition, the weight of an object is equal to the magnitude of the force of gravity acting on it. This means that even a "weightless" astronaut in low Earth orbit, with an apparent weight of zero, has almost the same weight as he would have while standing on the ground; this is due to the force of gravity in low Earth orbit and on the ground being almost the same.
An object that rests on the ground is subject to a contact force exerted by the ground. The contact force acts only on the boundary of the object that is in contact with the ground. This ground reaction force is transferred into the body; the force of gravity on every part of the body is balanced by stress forces acting on that part. A "weightless" astronaut feels weightless due to the absence of these stress forces. By defining the apparent weight of an object in terms of contact forces, one can capture this effect of the stress forces. A common definition is "the force the body exerts on whatever it rests on."[1]
The apparent weight can also differ from weight when an object is "partially or completely immersed in a fluid", where there is an "upthrust" from the fluid that is working against the force of gravity.[2] Another example is the weight of an object or person riding in an elevator. When the elevator begins rising, the object begins exerting a force in the downward direction. If a scale were used, it would be seen that the weight of the object is becoming heavier because of the downward force, changing the apparent weight.[3]
The role of apparent weight is also important in fluidization, when dealing with a number of particles, as it is the amount of force that the "upward drag force" needs to overcome in order for the particles to rise and for fluidization to occur.[4]
Referencesedit
^Beiser, Arthur (2004). Schaum's outline of theory and problems of applied physics. McGraw-Hill Professional. pp. 59–60. ISBN9780071426114. Retrieved December 22, 2011. apparent weight.
^Ramtal, Dev; Dobre, Adrian (2011). Physics for Flash Games, Animation, and Simulations. Apress. pp. 196–197. ISBN9781430236740. Retrieved December 22, 2011.
^Oman, Robert M.; Oman, Daniel M. (1997). How to solve physics problems. McGraw-Hill Professional. pp. 71–75. Retrieved December 22, 2011. apparent weight.
apparent, weight, physics, apparent, weight, property, objects, that, corresponds, heavy, object, appears, apparent, weight, object, will, differ, from, ordinary, weight, object, whenever, force, gravity, acting, object, balanced, equal, opposite, contact, for. In physics apparent weight is a property of objects that corresponds to how heavy an object appears to be The apparent weight of an object will differ from the ordinary weight of an object whenever the force of gravity acting on the object is not balanced by an equal but opposite contact force By definition the weight of an object is equal to the magnitude of the force of gravity acting on it This means that even a weightless astronaut in low Earth orbit with an apparent weight of zero has almost the same weight as he would have while standing on the ground this is due to the force of gravity in low Earth orbit and on the ground being almost the same An object that rests on the ground is subject to a contact force exerted by the ground The contact force acts only on the boundary of the object that is in contact with the ground This ground reaction force is transferred into the body the force of gravity on every part of the body is balanced by stress forces acting on that part A weightless astronaut feels weightless due to the absence of these stress forces By defining the apparent weight of an object in terms of contact forces one can capture this effect of the stress forces A common definition is the force the body exerts on whatever it rests on 1 The apparent weight can also differ from weight when an object is partially or completely immersed in a fluid where there is an upthrust from the fluid that is working against the force of gravity 2 Another example is the weight of an object or person riding in an elevator When the elevator begins rising the object begins exerting a force in the downward direction If a scale were used it would be seen that the weight of the object is becoming heavier because of the downward force changing the apparent weight 3 The role of apparent weight is also important in fluidization when dealing with a number of particles as it is the amount of force that the upward drag force needs to overcome in order for the particles to rise and for fluidization to occur 4 References edit Beiser Arthur 2004 Schaum s outline of theory and problems of applied physics McGraw Hill Professional pp 59 60 ISBN 9780071426114 Retrieved December 22 2011 apparent weight Ramtal Dev Dobre Adrian 2011 Physics for Flash Games Animation and Simulations Apress pp 196 197 ISBN 9781430236740 Retrieved December 22 2011 Oman Robert M Oman Daniel M 1997 How to solve physics problems McGraw Hill Professional pp 71 75 Retrieved December 22 2011 apparent weight Rhodes Martin J 2008 Introduction to particle technology John Wiley and Sons pp 169 171 ISBN 9780470014271 Retrieved December 22 2011 Retrieved from https en wikipedia org w index php title Apparent weight amp oldid 1187786366, wikipedia, wiki, book, books, library,
