A model of a helicopter rotor has four blades, each of length 3.50 m from the central shaft to the blade tip. The model is rotated in a wind tunnel at a rotational speed of 540 rev/min a) What is the linear speed of the blade tip? (b) What is the radial acceleration of the blade tip expressed as a multiple of g?

Question

Physics

Luciana Moss

4 December, 07:00

A model of a helicopter rotor has four blades, each of length 3.50 m from the central shaft to the blade tip. The model is rotated in a wind tunnel at a rotational speed of 540 rev/min a) What is the linear speed of the blade tip? (b) What is the radial acceleration of the blade tip expressed as a multiple of g?

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Answers (1)

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Micaela Abbott · Answer 1

a) v = 198 m/s

b) α = 11201 m/s² = 1143 g

Explanation:

a) v = rw

r = 3.50 m, w = 2πf

f = 540 rev/min = 9 rev/s

w = 2πf = 2π * 9 = 56.57 rad/s

v = 3.50 * 56.57 = 198 m/S

b) Radial acceleration, α = v²/r = 198²/3.5 = 11201 m/s²

Dividing by g = 9.8 m/s²,

α = 1143 g