A particle of mass 1 kg is subjected to a force which depends on the position as F = -k( x + yj) kg ms (1/2 i + )) m with k = 1 kg s. At time t = 0, the particle's position 7 = -+2m and its velocity v = (-2 + 2) + -2+2j+kms, k)ms"'.: T velocity, respectively. Ignore gravity. When z = 0.5 m, the value of (x vy - y vx) is Let v, and vy denote the x and the y components of the particle's m s .