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Doyouevenlift
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A rescue helicopter of mass 810 kg, supports itself in a stationary position by imparting
a downward velocity, v, to the air in a circle of radius 4.0 m. The density of the air is
1.20 kg m-3.
Calculate:
(i) the value of v
(ii) the power, P, required to support the helicopter
So, I do have the solution to part one, which is 11.5 ms-1. However, the solution for ii eludes me. The answer sheet does something weird:
Power = 0.5(pi*4^2)(1.2)v^3. From the first term I'm guessing they're using E=.5mv^2, but why is the velocity raised to the third?
a downward velocity, v, to the air in a circle of radius 4.0 m. The density of the air is
1.20 kg m-3.
Calculate:
(i) the value of v
(ii) the power, P, required to support the helicopter
So, I do have the solution to part one, which is 11.5 ms-1. However, the solution for ii eludes me. The answer sheet does something weird:
Power = 0.5(pi*4^2)(1.2)v^3. From the first term I'm guessing they're using E=.5mv^2, but why is the velocity raised to the third?
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