L = length of the chain = 3 m
θ = angle with the vertical = 49 deg
h = height gained
In triangle ABD
Cosθ = AB/AD
Cosθ = AB/L
AB = L Cosθ
BC = AC - AB = L - L Cosθ
so h = L - L Cosθ
inserting the values
h = (3) - (3) Cos49 = 1.032 m
v = maximum speed at the bottom of the swing
Using conservation of energy
kinetic energy at the bottom of the swing = potential energy at the maximum height
(0.5) m v² = mg h
v = sqrt(2gh)
v = sqrt(2 x 9.8 x 1.032)
v = 4.5 m/s
