Question

A solid bowling ball with mass 7.0 kg and diameter 24 cm rolls without slipping at 5.2 m/s. Find its rotational kinetic energy.

Answer 1

first thing i did was convert 24 cm to .24 m and divide that in have to get my radius=.12m

the formula i used was KE = (.5)*Inteia*angualr velocity^2

to find my angular velocity i used V=angular velocity * r which gives me 43.33rad /s
to find interia i used I=mass1*radius^2 which gives me 0.1008

i plug those two into the orginal into the first equation which gives me 95 J.
I input that into my answer, but it says that i was incorrect. but, when i input that answer into my transitional kinetic energy i was correct.

i do not know where i went wrong and is transitional and kinetic energy two different things?

Answer 2

i meant to say transitional and rotational kinetic energy are two different things.