Ek = (m*V^2) / 2 where m is mass and V is speed, then we can take this equation and manipulate it a little to isolate the speed.
Ek = mv^2 / 2 — multiply both sides by 2 2Ek = mv^2 — divide both sides by m 2Ek / m = V^2 — switch sides V^2 = 2Ek / m — plug in values V^2 = 2*30J / 34kg V^2 = 60J/34kg V^2 = 1.76 m/s — sqrt of both sides V = sqrt(1.76) V = 1.32m/s (roughly)