Question

A turbine is spinning at 3400 rpm. Friction in the bearings is so low that it takes 16 min to coast to a stop. How many revolutions does the turbine make while stopping?

Answer 1

Answer:

N = 27,887 revolution

Explanation:

given,

turbine is spinning = 3400 rpm

time = 16 min = 16 × 60 = 960 s

$\omega_i = \dfrac{2\pi\ N}{60}$

$\omega_i = \dfrac{2\pi\ 3400}{60}$

$\omega_i = 356.05\ rad/s$

$\omega_f = 0$

$\theta = (\dfrac{\omega_i+\omega_f}{2})t$

$\theta = 2 \pi N$

$2 \pi N = (\dfrac{356.05+0}{2})\times 960$

$N = \dfrac{(\dfrac{356.05+0}{2})\times 960}{2 \pi}$

N = 27,887 revolution