A child is swinging at a playground. The chain of the swing has a length of 4 meters, the child has a mass of 30 kg. a) As the child begins swinging, what is the period of oscillation? b) Now a larger child comes along. This child has a mass of 50 kg and is taller, so he winds the chain up a bit to raise the swing farther off of the ground. The new length of the swing is 3.5 meters. What is the period of oscillation now? c) In the new setup, the swing begins 1.0 meter above the ground. The older child swings until he is 2.0 meters above the ground. At what speed is the swing moving when the child goes through the bottom of the swing's motion, the lowest point? d) If the chain were kept at that length, but the younger child were swinging instead of the older child, what would the speed be?