Question

A wind turbine is rotating 5.98 rad/s when the wind abruptly stops blowing. It takes the turbine 27.5s to stop rotating. how many revolutions does his turbine make before it comes to a stop

Answer 1

S = Vo t * 1/2 a t^2 equation for distance traveled

w = w0 t + 1/2 a t^2 equivalent circular equation where w equals omega

w = 5.98 * 27.5 + a (27.5)^2/ 2

a = (w2 - w1) / t = -5.98 / 27.5 = -.217

w = 5.98 * 27.5 - 1/2 * .217 * 27.5^2 = 82.4

Since 1 Rev = 2 pi radians

Rev = 82.4 / 2 * pi = 13.1 Rev