Can Someone help me With my Physics Homework? please?

Question

A discus traveling at 20.0 m/s has 330 j of kinetic energy. Find the mass of the discus.
Please can someone help me through this i keep comin up with the wrong answer?

Answer 1

v = 20.0m/s
Ek = 330 J
m = ?

=> so you use the Ek = 1/2mv^2

330 m/s = 1/2(m)(20m/s^2)

=>bring the 1/2 over
330*2=m(20^2)
660=m(20^2)

=>square 20
660=m(400)

=> bring 400 over, so you have to divide it
660/400 = m

so mass = 1.65 kg

:)

Answer 2

1 joule = 1kg * m2 / s2

330j = x * (20m/s)^2
330j = x * 400m^2/s^2
.825 kg = x
or 825g = x