Difference between revisions of "Terminal fall velocity"

From Glossary of Meteorology
imported>Perlwikibot
(Created page with " {{TermHeader}} {{TermSearch}} <div class="termentry"> <div class="term"> == terminal fall velocity == </div> <div class="definition"><div class="short_definition">(<br...")
 
imported>Perlwikibot
 
Line 9: Line 9:
 
   </div>
 
   </div>
  
<div class="definition"><div class="short_definition">(<br/>''Or'' terminal velocity.) The particular falling speed, for any given object  moving through a fluid medium of specified physical properties, at which the [[drag]] forces and  buoyant forces exerted by the fluid on the object just equal the gravitational force acting on the  object. It falls at constant speed, unless it moves into air layers of different physical properties.</div><br/> <div class="paragraph">In the [[atmosphere]], the latter effect is so gradual that objects such as raindrops, which attain  terminal [[velocity]] at great heights above the surface, may be regarded as continuously adjusting  their speeds to remain at all times essentially in the terminal fall condition. The terminal fall  velocity of water droplets in still air can be computed from [[Stokes's law]] for drops smaller than  80 &#x003bc;m in diameter. Above that size, empirical values must be used.</div><br/> </div>
+
<div class="definition"><div class="short_definition">(''Or'' terminal velocity.) The particular falling speed, for any given object  moving through a fluid medium of specified physical properties, at which the [[drag]] forces and  buoyant forces exerted by the fluid on the object just equal the gravitational force acting on the  object. It falls at constant speed, unless it moves into air layers of different physical properties.</div><br/> <div class="paragraph">In the [[atmosphere]], the latter effect is so gradual that objects such as raindrops, which attain  terminal [[velocity]] at great heights above the surface, may be regarded as continuously adjusting  their speeds to remain at all times essentially in the terminal fall condition. The terminal fall  velocity of water droplets in still air can be computed from [[Stokes's law]] for drops smaller than  80 &#x003bc;m in diameter. Above that size, empirical values must be used.</div><br/> </div>
 
</div>
 
</div>
  

Latest revision as of 16:17, 20 February 2012



terminal fall velocity

(Or terminal velocity.) The particular falling speed, for any given object moving through a fluid medium of specified physical properties, at which the drag forces and buoyant forces exerted by the fluid on the object just equal the gravitational force acting on the object. It falls at constant speed, unless it moves into air layers of different physical properties.

In the atmosphere, the latter effect is so gradual that objects such as raindrops, which attain terminal velocity at great heights above the surface, may be regarded as continuously adjusting their speeds to remain at all times essentially in the terminal fall condition. The terminal fall velocity of water droplets in still air can be computed from Stokes's law for drops smaller than 80 μm in diameter. Above that size, empirical values must be used.