Emily has a class assignment to study conservation of energy in collisions. She starts with two golf balls that hang from strings and hit each other when they swing. Emily finds her apparatus difficult to align so that the golf balls swing in the same plane. She borrows called Newton's cradle. It has five steel balls. How does it help improve her measurements? he device shown in the figure, which is called Newton's cradle. it has 5 steal balls. How does it help improve her measurements?