Which object has the greatest kinetic energy?

a
a fast pitched baseball with a mass of .5 kg moving at 46.9 m/s
b
a person with a mass of 73 kg running 6 m/s
c
a locomotive engine with a mass of 205,000 kg moving 5 m/s
d
a truck with a mass of 3,500 kg moving at 30 m/s

A fast pitched baseball with a mass of .5 kg moving at 46.9 m/s

a has (1/2) * .5 * 2199.61 = 550 J

b has (1/2) * 73 * 36 = 1314 J
c has (1/2) * 205,000 * 25 = 2,562,500 J
d has (1/2) * 3,500 * 900 = 1,575,000 J
the locomotive, C, wins :)

That half kg baseball would really have to move to have more Ke than a locomotive moving at all :)