Question

A model of a helicopter rotor has four blades, each 3.40 m long from the central shaft to the blade tip. The model is rotated in a wind tunnel at 550 rev/min. What is the radial acceleration (in m/s²) of the blade tip?

Answer 1

The radial acceleration

$$a=\omega^2R=(2\pi n)^2R\\ =(2*3.14*550/60)^2*3.40=1.23*10^4\:\rm m/s^2$$