def distance(v1, v2):
# simple function to calculate the distance between particle v1 and particle v2
return math.sqrt(Vec3.abs_sq(v1 - v2))
def energie_kin(massen, geschw):
kin = 0
for x in range(3):
# kinetische Energie = 1/2 * m * v²
kin += 1/2 * massen[x] * Vec3.abs_sq(geschw[x])
return kin
