You stand on a frictional platform that is rotating at 1.8 rev/s. your arms are outstretched, and you hold a heavy weight in each hand. the moment of inertia of you, the extended weights, and the platform is 9.3 kg * m^2. when you pull the weights in toward your body, the moment of inertia decreases to 5.1 kg * m^2.
(a) whatis the resulting angular speed of the platform?
(b) what is thechange in kinetic energy of the system?
(c) where did thisincrease in energy come from?

20.62361 rad/s

489.81804 J

Explanation:

= Initial moment of inertia = 9.3 kgm²

= Final moment of inertia = 5.1 kgm²

= Initial angular speed = 1.8 rev/s

= Final angular speed

As the angular momentum of the system is conserved

The resulting angular speed of the platform is 20.62361 rad/s

Change in kinetic energy is given by

The change in kinetic energy of the system is 489.81804 J

As the work was done to move the weight in there was an increase in kinetic energy

prolly a beacuse the momentuem the car has increases while going down hill

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