Question

what is the KE of a 0.2kg rolling ball travelling at a speed of 5m/s

Answer 1

(1/2) m v^2 = .5*.2*25 Joules

Answer 2

although it also has rotational energy Kinetic spin energy = (1/2)I omega ^2
= (1/2)(2/5) (.2)(R^2) omega^2
but v = R omega
so add
(1/2) (2/5)(.2) (25)