(a). Since K = W = Integral ( F dx ) and F = Fx = -6x K = -3 (x ^2) evaluate from 0 to 4 = 48 m/2 v^2 = 48 v = 6.9m/s correct? (b). since m/2 v^2 = -3x^2 and v = 5 x = sqrt ( -25/3 ) is not right because it would give me a complex number... Please advise!