Three solid cylinder rods roll down a hill with the same linear speed. Rod R1 has a 1inch diamter, Rod R2 has a 2inch diameter, and Rod R3 has a 3inch diameter. They all have the same masses. Rank in order the rotational energies of R!, R2, and R3.

a. E1 > E2 > E3
b. E3 > E2 > E1
c. E1 = E2 = E3

I say C based on the eaqution k=1/2(I)(omega)^2