Question #123782

The angular velocity of a disc of mass 3kg and radius 0.6m change from 10rev/s to 15rev/s in 0.07s. calculate the impulse on the disc.

Expert's answer

Angular momentum L (which change disc speed) can be found:

"L=J*(\\omega_{2} - \\omega_{1})"

where J - disc's moment of inertia, *ω*_{2} - finish angular speed *ω*_{1} - start angular speed.

Moment of inertia for disc can be found:

"J= \\frac{m\\times r^2}{2}"

where m - mass of the disc, r - radius of the disc.

Angular speed for correct calculation have to be transformed from rev/s to rad/s.

"1 rev\/s = 2\\times\\pi rad\/s"

So we have:

"L=\\frac{m\\times r^2\\times(\\omega_{2}-\\omega_{1})}{2}"

"L=\\frac{3\\times0.62\\times(15\\times2\\times\\pi - 10\\times2\\times\\pi)}{2}=16.956 \\frac{kg\\times m^2}{s}"

Learn more about our help with Assignments: MechanicsRelativity

## Comments

## Leave a comment