Question

A helicopter blade spins at exactly 100 revolutions per minute. Its tip is 5.00 m from the center of rotation. (a) Calculate the average speed of the blade tip in the helicopter’s frame of reference. (b) What is its average velocity over one revolution?\

Answer 1

Explanation:

It is given that,

A helicopter blade spins at exactly 100 revolutions per minute.

Its tip is 5.00 m from the center of rotation, r = 5 m

(a) Let v is the average speed of the blade tip in the helicopter’s frame of reference. Distance covered by the helicopter, $d=2\pi r$

In 100 revolutions, $d=200\pi r=1000\pi$

So, average speed of the blade tip in one second is given by :

$v=\dfrac{d}{t}$

$v=\dfrac{1000\pi\ m}{60\ s}$

v = 52.35 m/s

(b) The average velocity over one revolution is zero because the net displacement in one rotation is 0.

Hence, this is the required solution.