A `40 kg` flywheel in the from of a unifrom circular disc `200 cm`. in diameter is making `120` revolutions/minute. Calculate angular momentum. Moment of inertia of disc `= (1//2) mass xx ("radius")^(2)`.

Explanation

Here, `m = 40 kg, d = 200 cm`,
`r = (d)/(2) = (200)/(2) cm = 100cm = 1m`
`n = 120rps = (120)/(60)rps = 2rps, L = ?`
`L = I omega = ((1)/(2)mr^(2)) 2pi n = mr^(2) pin`
`= 40 xx 1^(2) xx (22)/(7) xx 2kg m^(2) s^(-1)`
`L = 251.4 kg m^(2) s^(-1)`