Answer :
The flywheel is solid cylindrical disc. Moment of inertial = ½ * mass * radius^2
Mass = 40.0 kg
Radius = ½ * 76.0 cm = 38 cm = 0.38 meter
Moment of inertial = ½ * 41 * 0.36^2
Convert rpm to radians/second
The distance of 1 revolution = 1 circumference = 2 * π * r
The number of radians/s in 1 revolution = 2 * π
1 minute = 60 seconds
1 revolution per minute = 2 * π radians / 60 seconds = π/30 rad/s
Initial angular velocity = 500 * π/30 = 16.667 * π rad/s
170 revolutions = 170 * 2 * π = 340 * π radians
The flywheel’s initial angular velocity = 16.667 * π rad/s. It decelerated at the rate of 1.071 rad/s^2 for 48.89 seconds.
θ = ωi * t + ½ * α * t^2
θ = 16.667 * π * 48.89 + ½ * -1.071 * 48.89^2
2559.9 - 1280
θ = 1280 radians