- #1
Faefnir
- 10
- 0
A flywheel with a inertia moment of ##245 kg \cdot m^2## rotates making 20 round per second. The wheel stops 20 minutes after a braking moment action. Calculate the intensity of the braking moment
$$ \omega = 20 \frac{round}{s} = 126 \frac{rad}{s} $$
$$ t = 20 min = 1200 s $$
The braking moment intensity is equal to the speed with which the angular moment changes. Because the wheel is stopped at the time ## t = 1200 s##
$$ t = 1200 s $$
$$ \Delta L = I \cdot \omega $$
$$ \tau = \frac{I \cdot \omega}{t} = \frac{245 kg \cdot m^2 \cdot 126 \frac{rad}{s}}{1200 s} = 25.725 N \cdot m $$
The text provides a result of ## 513 N \cdot m ##. What was wrong with reasoning?
$$ \omega = 20 \frac{round}{s} = 126 \frac{rad}{s} $$
$$ t = 20 min = 1200 s $$
The braking moment intensity is equal to the speed with which the angular moment changes. Because the wheel is stopped at the time ## t = 1200 s##
$$ t = 1200 s $$
$$ \Delta L = I \cdot \omega $$
$$ \tau = \frac{I \cdot \omega}{t} = \frac{245 kg \cdot m^2 \cdot 126 \frac{rad}{s}}{1200 s} = 25.725 N \cdot m $$
The text provides a result of ## 513 N \cdot m ##. What was wrong with reasoning?