13.A child swings back and forth on a swing set while a student makes measurements of the
child's motion. The student determines that, as the child swings, the child's center of
mass reaches a maximum height of 1.90 m above the ground and a minimum height of
1.20 m above the ground. Which of the following is the best estimate of the fastest
speed attained by the child as she swings?
a. 3.7 m/s
b. 4.9 m/s c. 5.6 m/s
d. 6.2 m/s
e. 7.9 m/s
