# Turntables#

A side view of three turntables is shown in the figure below. The curly arrow shows the direction of rotation. Turntable (i) is a disk of mass $$10$$ $$\rm{kg}$$ and supports a $$5$$ $$\rm{kg}$$ mass at each end as seen in the figure. Turntable (ii) is a disk of mass $$10$$ $$\rm{kg}$$ and supports two masses of $$5$$ $$\rm{kg}$$ each near its centre. Turntable (iii) is massless and supports $$10$$ $$\rm{kg}$$ of mass at each end.

## Part 1#

Rank the moments of inertia:

• $$I_{i}$$ > $$I_{ii}$$ > $$I_{iii}$$

• $$I_{iii}$$ > $$I_{ii}$$ > $$I_{i}$$

• $$I_{iii}$$ > $$I_{i}$$ > $$I_{ii}$$

• $$I_{ii}$$ > $$I_{i}$$ > $$I_{iii}$$

• All three have the same moment of inertia since they have the same total mass.