Force of gravity

A buoyant spherical particle of diameter D floating in a Hquid which has no tendency to wet, ie, pull the shoreline up, or to reject, ie, push the shoreline down, the soHd submerges to a depth d at which the downward force of gravity on the sphere equals the upward buoyancy force of the displaced Hquid. This occurs when... 

Pneumatic classification can be partitioned conveniently into coarse, ie, fine products above 95% < 100 pm intermediate, ie, fine products ranging between 95% < 100 and 30 pm and fine, ie, fine products below 95% < 30 pm. Pneumatic classification, like hydraulic classification, balances the force of gravity with drag forces (counter flow) in order to bring about a separation. 

Sedimentation. This is the traditional method of treating wastewater in lagoons and uses the force of gravity to remove settable soHds (50,51). These soHds are separated out as a watery sludge which is removed mechanically. 

Swing Check Valves These valves (Fig. 10-156) are used to prevent reversal of flow Normal design is for use only in horizontal lines, where the force of gravity on the disk is at a maximum at the start of closing and at a minimum at the end of closing. Unhke most other valves, check valves are more likely to leak at low pressure than at high pressure, since fluid pressure alone forces the disk to conform to the seat. For this reason elastomers are often mounted on the disk. Swing checkvalves are available with low-cost insert bodies. 

A gas-sohds contacting operation in which the sohds phase exists in a dilute condition is termed a dispersion system. It is often called a pneumatic system because, in most cases, the quantity and velocity of the gas are sufficient to lift and convey the sohds against the force of gravity. Pneumatic systems may be distinguished by two characteristics ... 

General Characteristics Countercurrent flow is maintained by virtue of the difference in densities of the hquids and either the force of gravity (vertical towers) or centrifugal force (centrifugal extractors). Only one of the liquids may be pumped through the equipment at any desired velocity. Tne maximum velocity for the second is then fixed if it is attempted to exceed this limit, the second hquid will be rejected and the extractor will be flooded. 

Solid-Bowl Centrifuge The Bird solid-bowl centrifuge uses powder instead of gravity and can develop centrifugal forces up to 1800 times the force of gravity. It is therefore a unique type in classification practice. 

Removal by Centrifugal Force. This method is more efficient in extracting the particulate matter from a liquid due to the fact that the forces devcT oped are many times greater than the force of gravity. 

Schwer-hSrigkeit, /. difficulty of hearing. -Industrie, /. heavy industry, -kraft, /. force of gravity, -kraftbeschleunigung, /. acceleration of gravity, -kraftfeld, n. gravitational field. -kraftstofF, m. heavy fuel, specif. Diesel... 

Matter itself has energy, called rest energy. Wliat distinguishes matter-energy from other forms of energy is that all matter has inertia and is subject to the force of gravity when at rest as well as when in motion. Inertia measures the resistance of an object to being accelerated by a force, and the inertia of an object at rest is proportional to its mass. 

Grease is a very important and useful lubricant when used correctly, its main advantage being that it tends to remain where it is applied. It is more likely to stay in contact with rubbing surfaces than oil, and is less affected by the forces of gravity, pressure and centrifugal action. Economical and effective lubrication is the natural result of this property and a reduction in the overall cost of lubrication, particularly in all-loss systems, is made possible. 

Grashof Gr Coefficient of expansion of fluid Density of fluid Viscosity of fluid Force of gravity Temperature difference Dimension of surface... 

For NRc S 10, the liquid motion moves with the impeller, and off from the impeller, the fluid is stagnant [34]. The Froude number accounts for the force of gravity when it has a part in determining the motion of the fluid. The Froude numbers must be equal in scale-up situations for the new design to have similar flow when gravity controls the motion [16]. 

We want to find the relation between the height, h, of the column of mercury in a barometer and the atmospheric pressure, P. Suppose the cross-sectional area of the column is A. The volume of mercury in the column is the height of the cylinder times this area, V = bA. The mass, ttt, of this volume of mercury is the product of mercury s density, d, and the volume so m = dV = dhA. The mercury is pulled down by the force of gravity and the total force that its mass exerts at its base is the product of the mass and the acceleration of free fall (the acceleration due to gravity), g F = mg. Therefore, the pressure at the base of the column, the force divided by the area, is... 

American physicist Robert A. Millikan and his student Harvey Fletcher designed an experiment to determine the charge on the electron. As shown in Figure 2-14. the apparatus was a chamber containing two electrical plates. An atomizer sprayed a mist of oil droplets into the chamber, where the droplets drifted through a hole in the top plate. A telescope allowed the experimenters to measure how fast the droplets moved downward under the force of gravity. The mass of each droplet could then be calculated from its rate of downward motion. 

The air around us is a huge reservoir of gas that exerts pressure on the Earth s surface. This pressure of the atmosphere can be measured with an instmment called a barometer. Figure 5 shows a schematic view of a simple mercury barometer. A long glass tube, closed at one end, is filled with liquid mercury. The filled tube is inverted carefully into a dish that is partially filled with more mercuiy. The force of gravity pulls downward on the mercury in the tube. With no opposing force, the mercury would all ran out of the tube and mix with the mercury in the dish. 

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