Where results make sense

About us   |   Why use us?   |   Reviews   |   PR   |   Contact us

Arrow Flight - Drag Firstly the direction of rotation from drag from the front of the shaft to the centre of gravity (CG) is in the opposite direction to the drag from the CG to the nock end of the shaft. The further forward the centre of gravity of the arrow is then the lower the proportion of the total drag on the shaft that moves the arrow and correspondingly a higher proportion of the total drag rotates the arrow. Drag on the pile can induce a rotational torque on the arrow if the pile is "bent" or has a shape such that the direction of the pile drag force is not directed through the overall centre of gravity of the arrow when having a high enough offset angle. homepage.ntlworld.com /joetapley/fdrag.htm   (1321 words)

Drag (physics) - Wikipedia, the free encyclopedia For a solid object moving through a fluid or gas, the drag is the sum of all the aerodynamic or hydrodynamic forces in the direction of the external fluid flow. The overall drag of an object is characterized by a dimensionless number called the drag coefficient, and is calculated using the drag equation. is the drag coefficient (a dimensionless constant, e.g. en.wikipedia.org /wiki/Drag_(physics)   (1196 words)

Terminal Velocity (gravity and drag) The direction of the drag is along the rocket axis and opposed to the motion of the rocket. The magnitude of the drag is given by the drag equation. Drag D depends on a drag coefficient Cd, the atmospheric density r, the square of the air velocity V, and some reference area A of the object. exploration.grc.nasa.gov /education/rocket/termvr.html   (970 words)

Falling in Water Gravity applies the same force to us in water as in air; the difference in the perceived force is because gravity is also pulling on the water as well. Unlike gravity, which is the same for all objects, drag is much, much more complex, and depends very highly on the characteristics of the fluid (including temperature, currents, etc) and the object being affected, including shape, mass, surface smoothness, direction, and velocity. The acceleration due to gravity of the Earth is still 9.8 meters per second squared, as long as you are near the surface of the Earth, regardless of what the object is falling through. www.newton.dep.anl.gov /askasci/phy99/phy99x88.htm   (2389 words)

AMS Glossary Gravity waves grow in amplitude as they propagate upward from their surface source regions into lower-density regions. Gravity wave drag plays an important role in explaining the zonal mean flow and thermal structure at higher atmospheric levels, particularly in the mesosphere. A plane gravity wave is characteristically composed of a pair of waves, the two moving in opposite directions with equal speed relative to the fluid itself. amsglossary.allenpress.com /glossary/browse?s=g&p=28   (957 words)

Race Car Design Tips and Information - Aerodynamics Drag, in vehicle aerodynamics, is comprised primarily of two forces. Flow detachment applies only to the "rear vacuum" portion of the drag equation, and it is really about giving the air molecules time to follow the contours of a car's bodywork, and to fill the hole left by the vehicle, it's tires, it's suspension and protrusions (ie. Drag coefficient, by itself is only useful in determining how "Slippery" a vehicle is. To understand the full picture, we need to take into account the frontal area of the vehicle. www.gmecca.com /byorc/dtipsaerodynamics.html   (2766 words)

[No title] I call this effect gravity drag, since it is exactly the equivalent to a drag on an object moving through a gravitational force field, and affects every object passing through a gravitational field. That is, the equilibrium orbit caused by gravity drag is circular, and around the equator of the sun or gravitational object. Remembering that the strength of the gravity drag depends on the strength of the gravitational field and the velocity through this field, it is apparent that velocity of motion of the point on the inner rim is slightly lower than that of the outer rim. www.geocities.com /newastronomy/SolarSystem.htm   (2121 words)

GW Santa Fe Gravity waves can act to transfer mean horizontal momentum from the ground to levels aloft in the atmosphere or from one layer of the atmosphere to another. She then went on to discuss calculations of the gravity wave field and mean flow forcing from a somewhat modified version of the Lindzen parameterization with an input spectrum consisting of 60 discrete waves widely distributed in horizontal wavelength (6 to 800 km) and period (7 minutes to 4 hours). The gravity wave drag seems to be crucial in producing the two day wave in the simulation, and Norton noted that when the drag is included a region of negative meridional gradient of zonal mean potential vorticity is created in the summer mesosphere. www.aero.jussieu.fr /~sparc/meetings/reports/SantaFe96.html   (5795 words)

Jiskha Homework Help - Features: Forum: speed of rocket Another factor that a rocket encounters during launch is the drag force on the vehicle produced by the dynamic pressure of the atmosphere on the nose of the vehicle. This drag is directly proportional to the air density, the frontal area of the rocket, and the square of the velocity. The total drag force may be calculated from the equation D = Cd(d)AV^2/2 where Cd (see sub d) is the total integrated drag coefficient of the vehicle, derived from wind tunnel tests, d is the mass density of the atmosphere, A is the frontal area of the rocket, and V is the velocity. www.jiskha.com /features/forum/display.cgi?id=1125006841.1125007633   (1449 words)

Met Office: Gravity wave drag The total drag depends on the wind speed, density and static stability of the low-level flow, where the low-level flow is that layer of air which intersects the sub-grid orography. The drag calculation accounts for the shape (anisotropy) of the sub-grid orography by orienting the drag vector to be perpendicular to the major axis of the sub-grid orography. The total drag is partitioned into low-level flow-blocking and gravity-wave drag components depending on the low-level Froude number. www.met-office.gov.uk /research/nwp/numerical/physics/gravity.html   (159 words)

Adventures In Skydiving - Gravity and Drag As he accelerates the amount of drag increases, because the faster an object moves through air, the greater the drag. Eventually drag is equal to the force of gravity. ...gravity and drag are once again equal and Philippe is again dropping at a constant velocity. www.seed.slb.com /en/scictr/watch/skydiving/gravity_drag.htm   (253 words)

Hitchhikers Guide to Model rocketry Drag, which is the air resistance on a rocket, appears to be applied at a point called the center of pressure. Drag is the air resistance opposite the direction of the rocket's velocity with respect to the air. All drag on a rocket appears to be acting at this point, despite the fact that the air is pressing along the whole rocket. library.advanced.org /10568/aerodynamics/forces.html   (766 words)

[No title] The gravity wave drag parameterization used at NMC is a fairly crude approximation of gravity waves forced by flow over topography. Otherwise the stress is not absorbed with height until either 1) a critical level is encountered at which point the momentum flux vanishes or 2) the gravity waves break and generate turbulence from shear or convective instability or 3) from wave saturation. The vertical flux of momentum due to gravity wave drag is incorporated in the model by modifying A and B to become: wwwt.emc.ncep.noaa.gov /gmb/wd23ja/doc/web2/chap6.html   (2143 words)

ESM The reference-level drag is determined using the formulation by Pierrehumbert (1986), while the vertical distribution of the reference-level drag is obtained following the algorithm by Miller and Palmer (1986), which incorporates the ideas of wave-saturation and wave-dissipation by Lindzen (1981) and Eliassen and Palm (1960), respectively. In our earlier study (Kim 1996), we found that the magnitudes of gravity-wave drag are systematically different in January simulations using the two representations of orography in the mid-latitude northern hemisphere although the overall impact of gravity-wave drag on the mean fields is similar when using the standard version of orography or the envelope orography. Whereas the impact of gravity-wave drag and the envelope orography on the mean fields is similar, it is not necessarily true in terms of the individual components of simulated angular momentum budget. www.atmos.ucla.edu /~mechoso/esm/kim96.html   (2156 words)

Fun With Science - Space Capsules - Background Gravity and drag are the most significant forces a capsule and its contents — delicate instruments and humans — experience. Gravity is a property of matter and is one of the universal forces of nature that attracts one object to another. The drag experienced by a capsule depends on several factors, including the density of the air, the shape of the rocket, the amount of surface area, and the roughness of the rocket's surface. www.lpi.usra.edu /education/explore/capsules   (1946 words)

The Four Aerodynamic Forces   (Site not responding. Last check: 2007-11-06) The four forces of flight are: lift, gravity (or weight), thrust, and drag. An airplane in flight is the center of a continuous tug of war between the opposing aerodynamic forces of lift versus gravity and thrust versus drag. Thrust is generated by the propeller and opposes drag caused by air resistance to the frontal area of the airplane. www.mste.uiuc.edu /davea/aviation/fourForces.html   (355 words)

purevolume™ | Drag of Gravity   (Site not responding. Last check: 2007-11-06) There is no question Drag of Gravity is at the forefront of today's modern heavy rock scene. As one of Phoenix's most entertaining musical acts, Drag of Gravity embarks on a musical journey so intense and so invigorating that fans and critics leave concerts awestruck. Drag of Gravity hasn't posted a blog yet. www.purevolume.com /dragofgravity   (155 words)

Fluent NEWS - Summer 2005 - Drag Laws 101 Therefore, drag appears only when there is a gradient of velocity across an interface, which only happens when the phases on either side of the interface move with different velocities. The Gidaspow (G) drag law does this by using a combination of the WY drag law for regions where the particle volume fraction is below 20%, and the Ergun drag law, which was developed for fixed (packed) beds, elsewhere. Besides the form of the drag law, the momentum exchange term is strongly influenced by the diameter of the particle, bubble, or droplet, so it is very important that an appropriate value is used for this parameter. www.fluent.com /about/news/newsletters/05v14i2/a18.htm   (1296 words)

Gravity drag - Wikipedia, the free encyclopedia (via CobWeb/3.1 planetlab1.cs.uiuc.edu)   (Site not responding. Last check: 2007-11-06) In astrodynamics, gravity drag also frequently called gravity losses is inefficiency encountered by a spacecraft thrusting while moving against a gravitational field. If the gravity acceleration vector is $g$ and\; thethrustvector\; per\; unit\; mass\; (acceleration\; produced\; by\; the\; engine)\; is$ a$ ,\; then\; the\; actual\; acceleration\; of\; the\; craft\; is$ a-g$ ,\; while\; usingdelta-vat\; a\; time-rate\; of$ a$ ;\; that\; is,\; thedelta-vof\; the\; vehicle\; used\; is$ a/a-g$ times\; the\; actual\; increase\; in\; speed.$$$$$$$$$$ When applying delta-v against gravity to increase specific orbital energy, it is advantageous to spend delta-v at as high speed as possible, rather than spending some, being decelerated by gravity, then spending some more, or spending it at less than full capacity. links.nextforum.net.cob-web.org:8888 /Gravity_drag   (577 words)

Gravity drag - Wikipedia, the free encyclopedia (via CobWeb/3.1 planetlab1.cs.uiuc.edu)   (Site not responding. Last check: 2007-11-06) In astrodynamics, gravity drag (or gravity losses) is inefficiency encountered by a spacecraft thrusting while moving against a gravitational field. When applying delta-v against gravity to increase specific orbital energy, it is advantageous to spend delta-v at the highest speed possible, rather than spending some, being decelerated by gravity, then spending some more, or spending it at less than full capacity. For instance, gravity drag would reduce a 2.6 G thrust directed upward to an acceleration of 1.6 G, for an efficiency of less than 62%. en.wikipedia.org.cob-web.org:8888 /wiki/Gravity_drag   (732 words)

CD Baby: DRAG OF GRAVITY: Down Those constraints were very similar for Drag of Gravity, with one major exception: Barking Dog Sounds, the studio they chose, was their first project to record there. Drag of Gravity is "the weight of an absolute truth" so album titles such as: "Ditch" "Down," "Black Holes," and "Weight" were all considered. From those humble beginnings, I knew Drag of Gravity was heading for greatness and their new CD "Down" emphasises their dedication to music and to God. cdbaby.com /cd/dragofgravity   (639 words)

Make time for space-time Eventually Einstein concluded that gravity was an effect of the space-time through which objects fall. So instead of thinking of gravity as just a depression in the "fabric" of space-time, we must think of it -- for spinning objects -- as a whirling depression -- kind of an upside-down tornado. Einstein concluded that gravity was a property of space-time, not a separate force. whyfiles.org /052einstein/frame_drag4.html   (730 words)

//Gravity Tutorial : Keith Peters : Bit-101.com Gravity will pull it in a positive y direction - adds a positive y value to it - until its yspeed reaches 0, then it starts falling down again, its yspeed becoming positive. Drag is a factor that reduces any speed by a small percent - xspeed and yspeed in any direction. Things like friction, gravity and position of the walls, floor and ceiling are not really properties of the ball, but of the surrounding world or environment. www.bit-101.com /tutorials/gravity.html   (2821 words)

Chapter 19 BALLISTICS AND THE FIRE CONTROL PROBLEM Because the drag force is continuously retarding the velocity of the weapon, the force of drag itself is continuously changing over the entire time-of-flight of the weapon, with drag dependent upon velocity and in turn velocity dependent upon drag. The force of drag constantly changes in magnitude as a function of velocity and in direction as a function of the direction of motion of the weapon. The center of gravity of the projectile, however, follows the curved path of the trajectory, and the instantaneous direction of its motion, at any point, is that of the tangent to the trajectory at that point. www.fas.org /man/dod-101/navy/docs/fun/part19.htm   (3342 words)

Theoretical and Experimental Dissection of Gravity-Dependent Mechanical Orientation in Gravitactic Microorganisms -- ... and the sine of the orientation angle to the gravity vector ( Movements of a larva in ASW (a and c) and of another in P-ASW (b and d) are shown at 3-s intervals in the same way as in Figs. of gravity toward the rear of the cell. www.biolbull.org /cgi/content/full/201/1/26   (3779 words)

National Kite Month A kite is effected by thrust, drag and by gravity. Gravity is the downward force created by the weight of the kite. All of these forces - lift, drag, gravity, and the thrust of the wind come together in the kite at a place called the center of pressure. www.nationalkitemonth.org /kids/whykitesfly.shtml   (671 words)

UGAMP Newsletter: Issue 16 January 1997 This deposits all the vertical momentum flux of the parametrized gravity waves over a relatively small vertical height range and hence produces large drag on the mean flow, which in the northern hemisphere near 80 km is over 200 m/s/day. Examination of the zonal mean temperatures (not shown) shows that the summer mesopause temperatures are 120 K for the strong gravity wave drag run (which is probably too cold by about 10 K), and 160 K for the weak gravity wave drag run (which is too warm). The amplitude of the tides in the strong gravity wave drag run is considerably smaller than in the weak gravity wave drag run. www.atm.ch.cam.ac.uk /acmsu/newsletter16/ugcm.html   (1014 words)

Science Project 2004 Gravity is the force that pushes you down when you jump. Gravity is the force that draws an object toward the ground. Drag is the only problem that gets in engineers ways that is what they are trying to prevent. www.selah.k12.wa.us /SOAR/SciProj2004/TylerS.html   (1047 words)

EXSS 323 Week 9/10 At a running speed of 5 m/s this runner will have a drag force considerably less than 48 N (plug in to the equation and see that the drag force would be 12 N). Lift and Drag forces are also affected by the "angle of attack" of an object moving through a medium. The lift and drag forces are always perpendicular to each other but will have varying magnitudes as an object's angle of attack is changed. oregonstate.edu /instruct/exss323/week9.htm   (707 words)

Try your search on: Qwika (all wikis)

About us   |   Why use us?   |   Reviews   |   Press   |   Contact us   Copyright © 2005-2007 www.factbites.com Usage implies agreement with terms.