Wind Definition and 829 Threads

[SOLVED] The Angle of the Launch of a Rocket against a Strong Wind Homework Statement A 1210-kg rocket is launched with an initial velocity v = 85 m/s against a strong wind. The wind exerts a constant horizontal force F= 8650 N on the rocket. At what launch angle will the rocket achieve its...

A windmill power generator converts a fixed fraction of wind energy into electrical energy.. Supposing the wind falls on the windmill at a speed v...[wind speed=v] What is the total electrical output proportional to..? 1.v^2 2.v^3 3.v 4.v^4

Homework Statement iam doing an assignment on renewable energy, specifically wind power. basically, i wish to know what are all and any principals, laws and theories that you can think of involved in this system. i just wish to know the names, i can do the research (no matter how difficult or...

[SOLVED] Aeordynamics, drag, wind resistance - table with Cw values for objects Hello I am not using the standard template as this is a minor question in relation to my assignment, and not the actual questions from the assignment itself. I am calculating the curve of a projectile fired at...

Hello! I'm doing a research work about projectiles and i thought of crossbow system. I am currently studying using these articles: http://ciencia.hsw.uol.com.br/framed.htm?parent=crossbow.htm&url=http://www.stortford-archers.org.uk/medieval.htm and...

http://www.guardian.co.uk/environment/2007/dec/10/politics Thousands of new off-shore wind turbines could power every home in Britain by 2020, the government will say today, as it announces new wind energy plans. John Hutton, the secretary of state for business, enterprise and regulatory...

I would like to understand the "standard" explanation for the acceleration of solar wind particles as they leave the solar surface. Could someone help me out? I'm specifically interested in explaining this sort of image from the European Space Agency...

If the wind speed is 5m/s at 10masl. How can i calculate the wind speed at 88masl with a surface roughness coefficient of 0.3? Cheers

Hi everyone. I am having extreme trouble finding the answer to this problem. I thought I originally had it, but nope. The original Q is: "Assume a wind turbine with a hub 50 meters above the ground, a rotor diameter of 65 meters and a wind-conversion efficiency of 25 percent. The turbine...

can anyone give me the flux of solar wind reaching earth...the number of electrons/protons /cm^2/sec reaching Earth from Sun...i searched many sites but couldn't get the value...

I've scanned some literature, but could not find a description of the mechanism that causes the "thin vertical wind"* from the accretion disk of a quasar. Can someone please explain or point me to an accessible paper? *Elvis M., 2000, Astrophysical Journal 545, 63

I took a recent flight from LAX to SFO on an Airbus 319 and noticed that there was a lot more turbulence than normal. So much so that the plane had to fly at its service ceiling, and even then, there was a good amount of shaking. I even had a mini panic attack and had to call a flight attendant...

Homework Statement The graph shows the speed as a function of time for a minivan, coasting on neutral along a straight, level road, loaded with windsurfing equipment and towing a boat.The total mass is 2450kg (weight = 5402lbs). Find the size of the force due to wind and rolling friction when...

Homework Statement The posture of small animals may prevent them from being blown over by the wind. For example, with wind blowing from the side, a small insect stands with bent legs; the more bent the legs, the lower the body, and the smaller the angle . The wind exerts a force on the insect...

1. Jane, whose mass is 49.0 kg, needs to swing across a river filled with man-eating crocodiles in order to rescue Tarzan, whose mass is 80.0 kg. However, she must swing into a constant horizontal wind force F on a vine that is initially at an angle of with the vertical. (See Fig. P5.73.) In the...

City A lies directly west of City B. When there is no wind Captain Dare A. Devil makes a round trip of 6000 km between the two in 10 hours in his airplane while traveling at same speed up and down. Once a strong steady wind was blowing from west to east, and the round trip took him 12 hours. How...

How does a rocket get tested in a wind tunnel? what is it's orientation? an airplane is facing the air, like in reality, as it flies. so does that mean you mount a rocket vertically, but have the wind come on the side? or do you mount it pointing in the direction of the wind? and does...

A 100-meter dash is run on a track in the direction of \vec{v} = 2\vec{e_{1}}+6\vec{e_{2}} . The wind velocity \vec{e}_{1}+\vec{e_{2}} km/h. The rules say that a legal wind speed measured in teh direction of the dash must not exceed 5 km/h. Will the race results be disqualified due to an illegal...

I believe this has just been tested (again) yesterday (Sept 17th/07) From: http://www.scenta.co.uk/scenta/news.cfm?cit_id=1217038&FAArea1=widgets.content_view_1&search_text1=&startrow1=16 The electric car just got a boost from the power generated by its own wind...! Article from JCNNetwork...

A 100-meter dash is run on a track in the direction of \vec{v} = 2\vec{e_{1}}+6\vec{e_{2}}. The wind velocity \vec{w} is 5\vec{e}_{1}+\vec{e_{2}} km/h. The rules say that a legal wind speed measured in teh direction of the dash must not exceed 5 km/h. Will the race results be disqualified due to...

Homework Statement A 54 kg skier skis directly down a frictionless slope angled at 12° to the horizontal. Choose the positive direction of the x-axis to be downhill along the slope. A wind force with component Fx acts on the skier. What is Fx if the magnitude of the skier's velocity is (a)...

Hello everyone, I would just like to know these few things, since I'm trying to build my own little variation of a wind tunnel for my experiment with sound. 1. How is the velocity of the wind inside the tunnel measured? 2. Following the first question, how then would I go about...

This isn't really a homework problem, but I am doing a research paper on the topic 'the Speed of sound in different air velocities'. I was just wondering is this is an appropriate topic, and whether or not I would be able to research and collect enough data for a 4000 word essay. Any...

Hey, got a bit of a problem; got a few questions on wind Shear in Dams & retaining walls. Can anyody help http://img296.imageshack.us/img296/9366/image0003xb2.jpg Thanks Andy.

(I'm not sure if I posted this topic in the appropriate category. The project I'm discussing is for my school, but seems bigger and different than a homework question. If it's not the right section I'm sorry) I want to measure the relationship between various aspects of wind generated waves...

1. Homework Statement Air at 20 degrees celsius and 100kpa is drawn into a wind tunnel. If the deflection h of a water manometer that is connected to a hole in the wall of the test section to measure the gauge pressure in the flow is 98mm. Calculate air speed in test section in m/s ignore...

Homework Statement Air at 20 degrees celsius and 100kpa is drawn into a wind tunnel. If the deflection h of a water manometer that is connected to a hole in the wall of the test section to measure the gauge pressure in the flow is 98mm. Calculate air speed in test section in m/s ignore fluid...

If supposing we were to add a wind turbine connected to a generator to a moving car, would we be able to get the air flowing around the car to turn the turbine and therefore gain some energy? If it is possible, is it economical? if it is, is it practical? would there be a loss? would there be...

Having a little bit of trouble with this and not sure if my findings\thoughts are right and would like some insight. If a boat is traveling south at 10 km/h and a person on the deck measures the wind velocity to be 8 km/h east, would the actual wind velocity (velocity of wind relative to the...

Homework Statement I am working on making a small wind tunnel using a 20" fan. What i want to figure out is the force generated by the movement of air. I want to make the size of the tunnel shrink to help induce more velocity in the air (see picture). Homework Equations Bernoulli's...

POWER FROM A CONVECTION LOOP: this is a scaled down version of the solar tower updraft system planned for austrailia, or the SHPEGS project with water/silica jell adsorption instead of ammonia absorption, or the water spray downdraft 'culvert on a hillside', proposed for hot dry...

I need to test a model rocket which will have average airspeeds around 200 mph. I am hoping to construct a plexiglass box about 9 feet long, 3 feet wide and 3 feet tall. For these dimensions and airspeed requirements it looks like I'd need a 160000 cfm blower. Is this something I can feasibly...

I am trying to build a low speed wind tunnel, and have a question. I understand that the contraction cone speeds up the air (proportional to the area ratio). What I am confused on is how does this "mechanical advantage" factor into sizing my fan / motor? I am planning on a tunnel with a...

Homework Statement A sailboat is traveling east at 4.5ms-1. a suddent gust of wind gives the boat an acceleration a = 0.70 ms-2, 40 degress north to east. what are the boat's speed and direction 6s later when the gust subsides? Homework Equations V(@6s) = V(init.) + at The Attempt at a...

Homework Statement "Wind (density=1.29kgm^-3) blows over a flat roofed building of height 20m at 12ms^-1.The area of he roof is 100m^2.What is the magnitude and direction of the force exerted on the roof if the pressure difference between inside and outside is due solely to the fact that the...

Is there enough power coming from solar wind to some how collect and store as energy.

sir i am tying to make a wind electricity generator, but i am confused about selection of material that i have to use for the project. can hysterisis loop help me? how? what the graph will show to me? please explain. the use of steal magnet will make my generator light and more efficient or...

Why is it that air going at a high rate of speed always cold? For example, fans throws air at high speed and it's cold and when we, human blow air fast is always cold. WHY?

Hello, Is there people amongst you who have ever dealt with Wind Tunnel testing? I cannot find a special section for experiments in this forum... I have a few topic to launch! Thanks...

I'm doing an experiment (at A-Level) to see the efficiency of a wind turbine. I'm doing this by changing the number of blades and varying the wind speeds. I wondered if anyone had an equation that could look at efficiency? I have the current and the voltage (and wind speed). Sorry if I've...

Homework Statement A factory whistle emits sound of frequency f. On a day when the wind velocity is w from the north, what frequency will observers hear who are located, at rest, (a) due north, (b) due south, (c) due east, and (d) due west, of the whistle? What frequency is heard by a cyclist...

Hello, I am trying to work with an equation I have for force from wind on an enclosed building. The equation is two parts, consisting of Qz which relates the the gound structure to the building qz = CONSTANT * CONSTANT * CONSTANT * CONSTANT * V^2 * CONSTANT V being the velocity You then...

Homework Statement An airplane is flying at [80.0, 50.0(degrees)] m/s when there is no wind. Then the wind begind to blow at [18.0, -20 (degrees)] m/s. a) if the pilot does not change the heading of the plane what will be the resultant velocity over the ground? b) In order to maintain...

Homework Statement A sheet of aluminum of thickness .01 m lies in a parking lot. A wind blows over the top of the sheet. What is the minimum velocity that will cause the sheet to begin to rise: Assume the density of air is 1.18 kg/m^3 and aluminum is 2700 kg/m^3. Homework Equations...

Homework Statement Is this true? the observed doppler shift for sound waves depends only on the relative motion of the source and the receiver. Homework Equations this is a concept-like question The Attempt at a Solution If no, doesn't mean, wind will affect the doppler effect?

Hello, I have a small 300W wind turbine (Aero4gen). I also have a weather station which datalog's the wind speed/direction, ect... at intervals of 5 mins also there is a solar radiation sensor (photodiode) (0 to 3 volts). Anyway, i will not be needing the solar radiation datalogging facility...

Hmm, i have this cenario, there is a cannon and it's target, separated by a distance d, not necessaraly in the same heigh. what i need is a function that gives the velocity needed for the cannon ball reaches the target. PS: consider the angle 45°, there is wind velocity, but not air...

I've been thinking about the wind turbine (horizontal turbine - like an airplane propellor.) that I pass on the way downtown and I'm realizing I've been taking for granted how it works. Seems to me it's exactly opposite of an airplane wing. Rather than forward speed generating lift, you have...

Homework Statement hello everyone, Im new to this forum but i really need some help doing a physics assignment. I am trying to use Newtons second law and the equation for wind resistance(click link) to determine the the angle made by a specific velocity. The link to the assignment is...

Hi Group, Just wanted to find out : The solar wind particles are electrically charged and arrive at the earth with great speed, then get trapped by the magnetic field in the magnetosphere envelope round the Earth. Right...:biggrin: Now, what about quantity? please can you guys...