Answer:
v = 2.348 m/s
Step-by-step explanation:
Let:
h be the height of the child above the swing's low point,
v be the speed at the low point.
When the ropes make angle 3
25 deg. with the vertical:
h = 3.00(1 - cos(25)).
Equating potential energy at the high point to kinetic energy at the low point:
29.0 * 9.81 * 3.00(1 - cos(25)) = 29.0v^2 / 2
79.96 =29.0v^2 / 2
v = 2.348 m/s