Helicopter Definition and 205 Threads

A girl in a helicopter falls out when it was rising vertically at 10 m/s. The girl has a rope tied to her harness so she can be retireved. After 2.5 secs, how much rope has been pulled out of the helicopter? I know that this is essentially asking you to find the height that the helicopter...

[b]1. A helicopter has two blades , each of which has a mass of 240 kg and can be approximated as a thin rod of length 6.7 m. The blades are rotating at an angular speed of 45 rad/s. (a) What is the total moment of inertia of the two blades about the axis of rotation? (b) Determine the...

i want to build a helicopter at my home. i only have a wish, whaich is referred to as idea in physics. can some one tell me the guide points about it. the helicopter should be able to hold a single person or about 70 kg. i am in Pakistan, Karachi. i have no idea where to get all the equipment...

Hi. Please excuse me if this is just too banal for this site, but we have a long-standing "real-world" problem that we need answers for and I am smart enough to know that I need to ask others ( = you guys ) for help. We normally carry up to 19 passengers but, during training and occasionally...

Homework Statement A helicopter is ascending vertically with a speed of 5.5m/s. At a height of 100m above the Earth, a package is dropped from a window. How much time does it take the package to reach the ground? Homework Equations delta y = Vot + 1/2at^2 The Attempt at a Solution...

Homework Statement The height of a helicopter above the ground is given by h=2.55t^3, where h is in meters and t is in seconds. At 1.85 s, the helicopter releases a small mailbag. How long after its release does the mailbag reach the ground? Homework Equations The Attempt at a...

hi i was wondering about the russian helicopter death ray and if it was based on the russian multi beam klystrons and all in one technology. does it use tesla multi beam technology? thanks

Well at work today an argument arose - me and one other person disagreed with about 12 others...and the thing is I can't seem to see how they'd be right. What I want to know is - could a man stop a helicopter taking off? The people I'm disagreeing with seem to think he could if he was...

Homework Statement A 5400 kg helicopter accelerates upward at 2.17 m/s2. The acceleration due to gravity is 9.8 m/s2. What life force is exerted by the air on the propellers? Answer in N. Homework Equations Fnet=ma The Attempt at a Solution I am making the acceleration positive...

Homework Statement A helicopter flies directly toward a vertical cliff. when the helicopter is 700 m from the cliff face it transmits a sonar signal. it recives the reflected signal 3.4 s later. if the signal travels at a wind speed 350m/s, what is the speed of the helicopter. The Attempt...

Homework Statement A 12000- kg helicopter is lifting a 4000- kg truck with an upward acceleration of 0.9 m/s2. Calculate the force the air exerts on the helicopter blades. Homework Equations F = ma The Attempt at a Solution I have no idea! Please help!

Homework Statement A 13000- kg helicopter is lifting a 7100- kg truck with an upward acceleration of 2.1 m/s2. Calculate the force the air exerts on the helicopter blades. Do I use the apparent weight equation for this? Wapp = m(g + ay)

Homework Statement The height of a helicopter above the ground is given by h=3.00t^3, where h is in meters and t is in seconds. After 2.00s, the helicopter releases a small mailbag. How long after its release does the mailbag reach the ground? Homework Equations d=v_1t +...

Hi everyone, I am doing the research on helicopter aerodynamics. By applying the blade element theory and momentum theory we can determine the induced velocity at the balde, and we knew that, at a distance very far below the rotor, the induced velocity is two time of the corresponding value at...

Homework Statement A model of a helicopter rotor has four blades, each 3.20m in length from the central shaft to the blade tip. The model is rotated in a wind tunnel at 600rev/min. a.) What is the linear speed of the blade in m/s? b.) What is the radial acceleration of the blade expressed as...

Need Materials for "Stability and Control Helicopter" Hi everyboy ! I'm now very disappointed, it's beause I have googled the materials of "stability and control helicopter" and what I got is nothing but disapointment. So, I need your help for the materials. Is there anyone got them ? please...

Hi, I have some questions about helicopter aerodynamics. I have been searching the web (and this forum) up and down but I could not find the answer. Maybe you can help. I want to calculate the cruise and maximum speeds of a helicopter given the weight, motor power, height (assuming pressure...

A helicopter has two blades (see figure), each of which has a mass of 230 kg and can be approximated as a thin rod of length 6.7 m. The blades are rotating at an angular speed of 41 rad/s. (a) What is the total moment of inertia of the two blades about the axis of rotation? (a) Determine the...

Does anyone know how to calculate how much downwards force a helicopter would exert on the roof of a house if it hovered over it at 700ft? Thanks

I know the lift force equation is .5*rho*V^2*Area*Coefficient. But I was wondering in the real world how would you measure the lift force? I hope they don't just plug the values for the equations.

I'm doing background research on a real application. At high altitudes (and/or when people are shooting at you) helicopters can't stop and hover, but could snag a survivor or critically injured litter patient at around 30 knots (15 meters per second) A similar device (Fulton Recovery system)...

Me and a friend are having a dispute after watching the movie Underworld : Evolution. There's a scene in the movie where a character literally pulls a helicopter out of the air by pulling its fast rope straight down. Now I know it's Hollywood, but I started laughing at the reality of such an...

I know this is not as serious of a topic as you are all used to, but hopefully someone could help me out anyways? - Imagine a helicopter hovering inside a cargo jet, (the jet is flying at cruising speed). What would happen to the helicopter if it was pushed outside the jet, with no changes...

A 4600 kg helicopter accelerates upward at 2.0 m/s^2. What lift force is exerted by the air on the propellors? I don't know how to do it. Please help :confused:

Hi, I need help with this question At a publicity event, Ayida, a stuntperson, will jump out of a helicopter with a jetpack on her back. The jetpack allows her to achieve a net upward acceleration of 4.4m/s^2 for a single interval of maximun length 10s. Ayida wants to time the use of the...

A military helicopter on a training mission is flying horizontally at a speed of 65.0 m/s and accidentally drops a bomb (fortunately not armed) at an elevation of 250 m. You can ignore air resistance. How much time is required for the bomb to reach the earth?(s) How far does it travel...

In a free-body diagram of a helicopter carrying a suspended object, what force exists to keep the helicopter aloft? Is there a normal force from the rotors? Any help would be appreciated.

Parents meddling in student life http://news.bbc.co.uk/1/hi/education/4777053.stm It's likely to be a new phenomena in the UK since the introduction of fees - and a lot of parents paying for their kids to go to uni. For you US people, is it a common practice, if a parent pays for their...

I need some help with a question please. If a helicopter has a speed of 5.50m/s moving upward vertically and when at the height of 105m above Earth a box is dropped from the window how much time will it take to reach the ground?

Hi all I am Abhishek Jain, recently joined this group. I have one query which might have been previously asked/explained, but I still have problems in understanding it. I assume that the Earth is spinning clockwise at 1000 miles per hour. Suppose a helicopter is traveling anticlockwise to...

Hi, my first post to this forum: I'm curious whether the hanging mass of the fuselage beneath a helicopter rotor can be said to exhibit pendulum behavior. Specifically, in the case of a helicopter or other rotorcraft with a so-called teetering rotor, no torque is present at the rotor head...

Ok, I heard that you could make a cheap, but good helicopter, that's a 1-2 seater, relatively easy. How could this be done?

Hello! We all know that helicopters can hover, stand still in the air. As they do this, a powerful downwash, down-directed wind, results. This is very obvious when the helicopter is near the ground, since the downwash often kicks up a dust cloud. My question is this: How strong will this...

A small mail bag is released from a helicopter. The helicopter is rising with a constant speed of 1.5 m/s After 2.0 seconds, what is the VELOCITY of the mailbag? I use the equation Vf = Vi + a*t and a would be 9.8 m/s squared right?

There were two posts reltaed to this question but both of them are so contradictory; the question goes a 13,000kg helicopter accelerates upward at 0.41m/s^2 while lifting a 900kg car. to the nearest Newton what is the lift force exerted by the air on the rotors? now one post would be...

Hi all! All the way from Sweden comes a small question... Planning to build a simple RC helicopter which, in the first stage, only should be able to take off. My idea was to use either a small lawnmover engine, or one from a chainsaw and build the helicopter with two props, turning opposite...

For those with a strong death wish only.

This problem led to a debate in my physics class, which was never resolved. A helicopter holding a 70kg package from a rope 5m long is accelerating up at a rate of 5.2 m/s^2. Neglect air resistance. When the upward velocity of the helicopter is 30 m/s, the rope is cut and the helicopter...

Hi, Can someone help me out on this one ... A train is driving from one point to another at a constant speed. In the gangway of this closed train we let a RC-helicopter take off from the ground. What will happen with the helicopter, will he stay in the air near us or will he crash...

Can you give me the formula for taking off a helicopter? This formula must give the minimum force that produced by moth for taking off. :rolleyes: (i want to project a miniatur helicopter).Thanks... from eng. student

Okay...I am think that I am totally lost on this problem. A helicopter holding a 70-kilogram package suspended from a rope 5.0 meters long accelerates upward at a rate of 5.2 m/s^s. When the upward velocity of the helicopter is 30 meters per second, the rope is cut and the helicopter...

http://news.bbc.co.uk/2/hi/south_asia/4144405.stm This reminds me of some rare WWI film footage that shows the calvary charging on their horses, right along side the first tanks - a unique and brief moment in history, and certainly funny looking from our point of view. :biggrin:

Hello I want create a small model of aircraft or helicopter 30-50 cm long which can fly for 3-4 minutes just as a hobby how should i go about? Thanx

Well, I know this Q might look cheesy or silly...but: What is the major equation which decides if X disc with Y raduis with Z angular acceleration will carry M mass and "fly" with it...I am just concern about vertical movements...not the horizantal...Basically its about a hgelicopter moving in...

having some major issues with this unit, mainly since the homework was assigned and we haven't been lectured on it yet...so it's new to me. anyway, if anyone can help me out with this problem, that'd be awesome. -----A helicopter rotor blade can be considered a long thin rod. If each of the...

A 7850 kg helicopter accelerates upward at 0.545 m/s^2 while lifting a 1250 kg car. What is the lift force exerted by the air on the rotors? What is the tension in the cable ignoring its mass that connects the car to the helicopter? Net Force = ma, so I did (7850)(0.545) + (1250)(0.545) =...

This was on our news this evening. They showed film of a US Apache helicopter firing on a crowd of civilians. Since a news cerw was right there, we saw the reporter get hit and die right in front of the camera, just as others around him also died. Also...

A model of a helicopter rotor has four blades, each of length 3.90m from the central shaft to the blade tip. The model is rotated in a wind tunnel at a rotational speed of 480rev/min . A.) What is the linear speed of the blade tip? given R= 3.9 T = 480 would it just be V= 2*pi*R/t...

This might be a stupid question, but if a helicopter is moving at 5.0 m/s vertically, and one drops a ball off the helicopter, what is the original velocity of the ball?

Can a helicopter that has lost power to the main rotor blades land slowly enough so that nobody gets hurt? What would the terminal velocity of a freefalling helicopter be?