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Because as you increase altitude, the density of air decreases. To compensate for the decreased air density the rotor blades need a greater angle of attack, pushing the retreating blade closer to stall(reducing the maximum airspeed)
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Why can't rescue helicopters fly in low air pressure?
I've never heard that. However, helicopters are limited to the altitude that they can hover, which would limit a Rescue helicopter from picking up a stranded mountain climber. In the high altitude, the air is "thinner" which means the air pressure is less. This limits the effiency of the rotor blades. However, usually the first indication of a problem is when a helicopter tries to hover at high altitude and the tail rotor looses it thurst and the helicopter goes into an uncontrolled spin. This was common with the Bell Model 206B. Even though a helicopter may be limited to the altitude at which it can hover, that does not mean it can't fly at that altitude. If a helicopter maintains a high forward air speed, it can still fly over mountains; its only when it stops and hovers that it may have problems.
Does adding mass to a paper helicopter affect the rotation speed of the helicopter?
If you are adding mass to the outside of the blades, it will make the blades rotate much more slowly. However if you add mass to the inside of the blades it will increase the rotational speed, however more force will be needed to start the rotation.
A skydiver steps from a helicopter and falls for 5 seconds before reaching her terminal velocity During this 5 second interval her acceleration will?
increase- your speed will increase until terminal velocity is reached. From there it will stay constant.
To create friction in your hands what do you have to do?
You can increase the friction by increasing the roughness of the surface you are working on. Reduce the speed of the moving object, or increase the weight of the body you are working on. Increase the surface area of contact.
When an object is accelerating What is its speed?
It will have increase in speed with increase in time
Why as density altitude increase reduce speed of helicopter?
To compensate for the decreased air density the rotor blades need a greater angle of attack, pushing the retreating blade closer to stall(reducing the maximum airspeed)
What would be data for collecting data in a helicopter experiment?
The helicopter's altitude, distance traveled, speed/rate of travel, etc.
How do helicopter pilots use math?
Helicopter pilots use maths in the following ways:- 1 To note the altitude of the chopper. 2 To note the speed of the chopper. 3 To calculate the speed of the upcoming storm. 4 During Landing
Why do helicopters fly so slow?
What is the limiting factor for helicopter speed you ask? What happens to the rotor as the velocity of the helicopter increases? The relative speed of the tips of the rotors changes because of the wind speed. On the advancing side of the rotor the speed increases by the speed of the helicopter. On the retreating side of the rotor the speed decreases by the speed of the rotor. One of two things happens as the helicopter reaches a high speed: A: If it is a large rotor, the advancing blade will reach the sound barrier and sap energy from the rotor, slowing it. Significant damage may occur to the helicopter. B: If it is a smaller rotor, the retreating blade will slow to the point where stall occurs, and the helicopter will be forced into a turn while losing altitude and decreasing speed, then it will usually recover if altitude permits. Option B can be mitigated by increasing rotor RPM at higher speeds. In this case the rotor speed becomes the limiting factor, as the centrifugal forces at the root of the blade are quite incredible. Carter
Why are boats streamlined?
to increase the speed & reduce resistence of the boat
What are the uses of a gear train?
Either to increase speed and reduce torque or to decrease speed and increase torque while conserving mechanical energy.
When you increase cargo on a ship will it affect the boats speed and distance?
Generally it will reduce both speed and range.
Why can't rescue helicopters fly in low air pressure?
I've never heard that. However, helicopters are limited to the altitude that they can hover, which would limit a Rescue helicopter from picking up a stranded mountain climber. In the high altitude, the air is "thinner" which means the air pressure is less. This limits the effiency of the rotor blades. However, usually the first indication of a problem is when a helicopter tries to hover at high altitude and the tail rotor looses it thurst and the helicopter goes into an uncontrolled spin. This was common with the Bell Model 206B. Even though a helicopter may be limited to the altitude at which it can hover, that does not mean it can't fly at that altitude. If a helicopter maintains a high forward air speed, it can still fly over mountains; its only when it stops and hovers that it may have problems.
How is wind speed affected by altitude?
how does is wind speed affected by altitude
How do you increase speed on a Lennox blower motor The tech put it on lower speed last summer until we replaced the squirrel cage We did and how do we increase the speed now?
Reduce the size of the pulley on the motor
How do you control speed of a motor?
first do you reduce the voltage level or increase the load factor
Will the speed of an aeroplane be same which is flying at different altitudes and have same mach number 2?
no mach no is defined as ratio of local speed of aeroplane to speed of sound. As the altitude increases the True speed of aeroplane increases and speed of sound decreases because of reduction of ambient temperature Hence the value of their ratio should increase at an increasing rate with increase in altitude. Keeping the Mach No constant say, 2 means reduction of speed to a large extent so as to maintain constant Mach No. Therefore same Mach no the aeroplane at higher altitude is flying slower
