In: Physics
A helicopter propeller blade starts from rest and experiences a constant angular acceleration of 14.0 rad/s2. Find the speed of a point on the blade 5.60 m from the axis of rotation when the blade has completed 13 revolutions.
Using equation of rotational motion (iii), we have
2 = i2 + 2
where, i = initial angular speed of blade = 0 rad/s
= constant angular acceleration = 14 rad/s2
= angular distance completed by blade = 13 rev = 81.6 rad
then, we get
2 = (2) (14 rad/s2) (81.6 rad)
= 2284.8 rad2/s2
= 47.8 rad/s
Therefore, the speed of a point on the blade from the axis of rotation which will be given by -
v = r
v = [(5.60 m) (47.8 rad/s)]
v = 267.6 m/s