According to a seated woman, a 65.2-kg man runs with his 33.6-kg dog toward a 18.2-kg child who is running toward the man. The man and dog's speed is 3.45 km/h, and the child's speed is 1.45 km/h.
(a) According to the woman, what is the kinetic energy of the man-dog-child system?
(b) According to the man, what is the kinetic energy of the man-dog-child system?