Answer:
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
<span>Weight is directly proportional to mass.</span>
A. Condensation
Hope this helps!!!
Formula for final velocity: Vf= vi+(a*t)
Vi- initial velocity, a=acceleration, t-time
Vf=vi+(at)
Vf= 0+(9.8m/s*2.8s)
Vf= 27.44 m/s
The acceleration of the Earth when dropping something would be 9.8 m/s
Here is an reference that can help you answer problems like these.
Hope this helps and good luck :)
Start with what the paragraph is about and put it basically in your own words