What is the kinetic energy of an arrow that weights 324 grains traveling 294 fps ?

Ke = (1/2) m v^2

I have no idea what units you are working in. To get to scientific units:

324 grains * 64.8 milligrams/grain = 21*10^3 milligrams = 21 grams = .021 kg

294 ft/s * .305 m/ft = 89.7 m/s

(1/2)(.021)(89.7)^2 = 84.4 Joules