Question

a flywheel that rotates with a frequency of 300 revolutions per minute, stops within 2.5 minutes. Find how many revolutions the flywheel makes until it stops and its angular acceleration.

Answer 1

Answer:

Total revolutions = 375 revolutions

Angular acceleration = -120 revolutions/minute²

Explanation:

Given:

initial angular speed (ω₀) = 300 rpm

final angular speed (ω) = 0 rpm

time (t) = 2.5 minutes

Angular acceleration:

$\boxed{\omega=\omega_o+ \alpha t}$

$0=300+\alpha (2.5)$

$\alpha=-300\div 2.5$

   $=-120\ revolutions/minute^2$

Total revolutions:

$\boxed{\theta=\omega_o t+\frac{1}{2} \alpha t^2}$

$\theta=300(2.5)+\frac{1}{2} (-120)(2.5)^2$

  $= 375\ revolutions$