A person on a swing moves so that the support rods are horizontal at the turning points (Figure 3.47). Show that the centripetal acceleration of the person at the low point of the arc is exactly 2 g, regardless of the length of the rods. This means that the force on the rods at the low point is equal to three times the person€™s weight. (The vertical distance between the turning point and the low point equals the length of the rods.)