Wind Definition and 829 Threads

This is more of a confirmation that I got the facts right: Reading around, I found out that the solar wind travels from the Sun to the Earth at a mean speed of 400km/s. Does this mean that it takes around 4 days for a burst of solar wind to cause disturbances in the Earth's magnetic field...

hey everyone I'm in year 12 physics, and we have a project revolving around the physics of sport i selected golfing, and my initial aim is to investigate the inaccuracy associated with predicting the aerodynamic motion of a golf ball (max height, max distance). i selected this mainly...

[Please Help!] Find Initial Velocity (With Wind Factored In) I can't do it =\. Q: What equation would I use to find initial velocity? Given: Wind Speed, Wind Angle, Coordinates of Origin, Coordinates of End Point, (Distance), Projectile Mass, Theta (Angle to Use) Here's my repost from a...

wind speed? Homework Statement A car leaves point A and drives at 80.0km/h [E] for 1.50h. It then heads north at 60.0 km/h for 1.00 h and finally [30o W of N] at 100.0 km/h for 0.50 h, arriving at point B. a) Determine the displacement of point B from point A. b) A plane flies directly from...

Homework Statement A boat is 400 kg and cruising along with a constant speed of 4.0 m/s in a direction 30 degrees north of east. The boat suddenly begins to feel a force from the wind that is 45 degrees north of east and has a magnitude of 100N. After a 10 second period what is the velocity...

Homework Statement You are flying in a light airplane spotting traffic for a radio station. Your flight carries you due east above a highway. Landmarks below tell you that your speed is 52.0 m/s relative to the ground and your air speed indicator also reads 52.0 m/s. However, the nose of your...

Hey everyone, first time user here! I'm doing a lab experiment with a small open wind tunnel and I'm having some trouble figuring out how to calculate the airspeed in the test section. There is a digital pressure gauge displaying what I was told to be the dynamic pressure. The pressure...

Homework Statement Airplane flies over route in shape of triangle ABCD. Time(t1, t2, t3) of flying over sections AB, BC, CA are known. Lenght of sections is also known. During fly wind is present. velocity of wind is constant, and speed of airplane relative to wind is also constant. Find...

I know this question was already asked but I wanted to tackle it from a different angle. I saw allot of posts on how it would take too much gas to create the energy from the turbine but for the example let's say the car is electric. Now say we have a system where the turbine is in a...

Guys, i need some help on wind tunnels here. Basically i need to find out more on the operation principles behind wind tunnels. Basically, wind tunnels provide simulation environment of high speed (transonic) flows by mimicking the reynolds number on the actual flow, because of dynamic...

Hello guys, could you please help me to solve this problem? A student normally needs 15 seconds for a 100m sprint. One day favorable wind conditionshelp her to increase her speed by 2km//h. What is her time now? A) aprx. 13,8 sec. B) aprx. 13,6 sec. C) aprx. 13 sec. D) aprx. 14,2...

Homework Statement The physics of wind instruments is based on the concept of standing waves. When the player blows into the mouthpiece, the column of air inside the instrument vibrates, and standing waves are produced. Although the acoustics of wind instruments is complicated, a simple...

Hi, I am a Mechanical student, currently at my final year so I am to do my FYP aka Final Year Project with the title of hybrid power generator (solar + wind). My friend is in charge of the solar part while I am to design a vertical-axis wind turbine. I am clueless about from where should I...

ok guys I am an old guy that is useless at maths so i'd like your help. I have searched the net and this forum and i have found some formula but I am to thick to work it out even with an equation. https://www.physicsforums.com/showthread.php?t=117105 This isn't home work as i haven't been to...

Homework Statement An observer is in rest.A source of sound is in rest.A wind blows along the line joining the observer and the source.What all remain same in these: a.frequency b.velocity of sound c.wavelength Homework Equations f prime=f(v+w-vo)/(v+w-vs) Doppler effect The...

we need to make a wind turbine using this motor http://www.kidwind.org/xcart/product.php?productid=15&cat=79&page=1" the rules can be found here: http://www.mrmaloney.com/nssl/events/2009-2010/0910_4-jan-wind.pdf" We were thinking, since they will be using P=(I^2)R instead of P=IV to...

Homework Statement If wind blows at 24 m/s over your house, what is the net force on the roof if its area is 300 m squared? Homework Equations Bernoulli's equation? P1+1/2pv1sqrd+pgy1=P2+1/2pv2sqrd+pgy2 The Attempt at a Solution Really didn't know where to go with this. I...

guys I am trying to do calculations for coils that i want to use...i don't know how to do faradays law..this is the information i have... 2inch coils, 80 turns (4layers, 20turns each layer) average diameter is .75 inches. distance from magnet is .25inches. speed is 80turns in 1.123seconds...

Hi All, I have a problem in which I am trying to calculate the force of the windspeed, x, on a surface area of a moving object, y. I am applying this to a monorail model, where a monorail carriage (lets for this purpose assume its a rectangular box) with a surface area on one side is y, is...

Hello, I am new to this forum, I thought you guys could send me in the right direction. what I am trying to do is heat water with a wind turbine. the turbine produces 3 phase wild AC with voltage of 0 to 270V. related to wind speed. I am aware of the general practices with wind turbines-...

Homework Statement Consider a wind turbine farm that uses turbines with a blade span diameter of 80 m at a site subjected to wind speeds over the range of 4 to 32 m/s. Taking the overall efficiency of each turbine to be 25% and the air density to be 1.112 kg/m3, determine the electric power...

I've been wondering lately why the air currents don't travel in the same direction. The Earth spins constantly and each side is given roughly equal irradiance from the sun, so why does the wind not simply follow this direction (on a macro scale) of heat input? Instead it seems to mix quite...

Hi Guys, I have a project to hand in before xmas. Basically I have to design a connector for a Wind turbine Blade. ie the Blade root, the one that connects to the hub. for this I have to come up with original ideas, so I cannot use another current of previous blade root connector. I have to...

Why are Horizontal Axis Wind Turbines used more often than vertical axis when it looks like a vertical axis has more of an advantage? Please can you explain it simply?

Homework Statement This is a real world problem and not a problem in a book, so if you feel I am missing some information just let me know. A ball is flying at 25 m/s The wind is blowing perpendicular to the trajectory at .44704 m/s \rho = \frac{1.17 kg}{{m}^3} Cd = 1/2...

I'm not sure where to post this, so please excuse me if this is misplaced. I need help understanding how the terms are grouped in this formula for A = pressure normal to the roof. If any of you are familiar with this formula or can link me to a source containing better expressed formulas like...

Hi everybody, this is my first post on your forum and i hope someone can help me :) the problem is i can figure out how to approuch this problem :s i do know that the process of the air descending is adiabatic but still i can't get it :( thanks for your help guys in advance. Homework...

i'm currently discussing this with a friend. anyway. here is the conversation: he said It started as "If something doesn't have a mass, it cannot have a force", due to Newton's second law, F = ma (Force = Mass x Acceleration). Logically, if you substitute 0 in for the Mass, you will get a...

What are the percentages of types of generators commonly used in wind turbines? To clarify, what percentage are regular squirrel-cage machines? What percentage are doubly-fed machines, permanent magnet machines, synchronous machines, and so on. I'm looking for a general idea of these statistics.

The Basis of this question is that: * Rockets launched at an angle follow the path of a rectangular hyperbola when thrust greater than their mass is produced. * That rockets fall in the path of a parabola when thrust is no longer produced, this only applies when the rocket has both x and y...

What is the effect of wind turbines on the aerodynamic of the wind system? Since energy is conserved, will excessive turbines lead to a leakage of wind energy and transformed into mechanical energy? [or concert to heat?] Also, what is the effect of the local pressure? Thanks in advance.

Homework Statement http://img198.imageshack.us/img198/3834/relativeboatvelocity.jpg The note says "( Wind relative to boat is irrelevant! )" Why is it irrelevant?

I am trying to create a wind sculpture and I could use some help. The sculpture will have 3 points of rotation all driven by the wind. Visualize the letter "Y" and you will have the basic idea. The base has bearings allowing rotation as do both of the arms. My prototype model works to some...

I am an artist not a physicist, I do very much interactive art though, and as I am a bit geeky, I really love to get some physics tricks involved somehow. People get excited when there are little gizmos going and its just great! So this project that I am working on has me stumped...I want to...

Can you help with this question? I have a solid tube 10'D x 5'L with 2 42" drum fans in one end producing about 19,000CFM each. I need to know what the velocity will be at the end of the tube in M/S. Also, will the fans be more efficient if there is a seal around the opening where the fan...

I live in Wisconsin and I am looking for a wind tunnel where I can conduct a number of airfoil experiments. Since I am in high school, I am not yet affiliated with a university, so it is difficult for me to get in touch with lab technicians at universities. I have successfully contacted the...

Homework Statement Ok, an airplane weighs 6,000 (think of the airplane as a triangle) and one of the back two wheels is stationary and acts as a pivot. The airplane is on the ground. How fast does the wind need to be blowing to push the front wheel 90 degrees from the original location...

http://www.cnn.com/2009/TECH/science/06/16/high-altitude.wind.power/index.html Basically two designs, one a helium-filled turbine. The other would be a kite that goes up and down. Is this feasible? I see a major issue being the weight of cable that the device would need to support.

Hi all, I just looked at a thread involving a wind turbine on a car or something of that sort and I have a similar idea... but it does not involve a car. It is similar in the aspect of something creates energy , and you add something else to it to get more energy, but I'm not sure if the...

I'm pretty sure someone somewhere has already built one, I've gone over the concepts involved and it does seem both practical and possible. The idea is this: electric-powered car that is recharged by several wind-generators(essentially fans on the roof) that recharge the batteries once the car...

The below though experiment which i devised, raises some personal concerns about my understanding of thermodynamics and aerodynamics, based on the fact that they seem to predict different outcomes. If anyone out there could offer some insight into what would actually happen, it would be greatly...

I'm looking for a summer project and I'm thinking of building a wind turbine to generate additional power for our home. I want it connected to the grid so that it runs our meter backwards for times where we arn't using more power than we generate (on vacation or something, electric company has a...

I have a question about Reynolds Number and wind tunnel tests. Last semester a few students at my university were conducting wind tunnel tests on a small model of a truck, they were trying to find ways to reduce the drag in order to save fuel. I would guess they were testing at a Reynolds Number...

1.A hurricane wind blows across a 7.8 m x 12 m flat roof at a speed of 180 km/hr. What is the pressure difference? How much force is exerted on the roof? 2. Homework Equations P= p_atmos + pgd P=F/AThe Attempt at a Solution p = 101300Pa - (1.3)(9.8m/s^2)(93.6m^2) p = 100107.5Pa 100107.5Pa =...

Consider a 10 m/sec wind blowing against a perfectly rigid wall. I want to calculate the pressure the wind produces on the wall. I'm ignoring the details of the actual physics of compression and turbulence. I'm reducing the problem to one cubic meter of (incompressible) air with a mass of 1.2 kg...

Hello, I'm a senior year ME undergraduate and I'm building a low speed (velocity=30-45 m/s) wind tunnel for my college as a final year project. The initial size for the tunnel was 300mm x 300mm in the test section with an open circuit configuration. I've read some papers on the design...

A windy 0 °C day perceived as colder than a 0 °C day without wind. I find that strange, given that wind is just air particles with kinetic energy. When those speedy particle hit a body, they should give off some of their energy to that body in the form of heat. But instead cold is perceived by...

How does Wind speeds change as a function of elevation?

Im new to this forum and wanted to see what you think about my new patent pending design. My concept is...using a 2.5Mw wind turbine, refit 110'L rotor blades with a 10-12' diameter of concave vanes or paddles designed to capture max air thru a forced ducted system that is generated from a large...

As I live not far from Altamont Pass and often hike the wind energy area, I see the damage windmill blades do to birds by the number of dead ones on the ground. Also, these windmills are truly Star Wars ugly and insulting to the environment visually, not even considering what they do to birds...