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Terminal velocity is the maximum speed attainable by an object as it falls through a fluid (air is the most common example). It is reached when the sum of the drag force ( F d ) and the buoyancy is equal to the downward force of gravity ( F G ) acting on the object.
In the Western world prior to the 16th century, it was generally assumed that the speed of a falling body would be proportional to its weight—that is, a 10 kg object was expected to fall ten times faster than an otherwise identical 1 kg object through the same medium.
For astronomical bodies other than Earth, and for short distances of fall at other than "ground" level, g in the above equations may be replaced by (+) where G is the gravitational constant, M is the mass of the astronomical body, m is the mass of the falling body, and r is the radius from the falling object to the center of the astronomical body.
m is the mass of the falling object; g is the acceleration due to gravity (9.8 m/s 2) C d is the drag coefficient (~0.7 for head down position, ~1 for belly-to-earth position) [10] ρ is the density of the fluid through which the object is falling (1.23 kg/m 3 for air at sea level, and ~0.99 kg/m 3 [11] at the middle of the measurement zone ...
Early reentry-vehicle concepts visualized in shadowgraphs of high speed wind tunnel tests. The concept of the ablative heat shield was described as early as 1920 by Robert Goddard: "In the case of meteors, which enter the atmosphere with speeds as high as 30 miles (48 km) per second, the interior of the meteors remains cold, and the erosion is due, to a large extent, to chipping or cracking of ...
For reference, the time it would take an object to fall 100 metres (330 ft), the height of a skyscraper, is shown, along with the maximum speed reached. Air resistance is neglected. Body
Creeping flow past a falling sphere in a fluid (e.g., a droplet of fog falling through the air): streamlines, drag force F d and force by gravity F g. At terminal (or settling) velocity, the excess force F e due to the difference between the weight and buoyancy of the sphere (both caused by gravity [7]) is given by:
During this descent Baumgartner set the record for fastest speed of free fall at 1,357.64 km/h (843.6 mph), [2] [12] [5] making him the first human to break the sound barrier outside a vehicle. [ 38 ] [ 39 ] Baumgartner was in free fall for 4 minutes and 19 seconds, a fall time 17 seconds shorter than the record set during mentor Joseph ...