Question

A 20 kg child is on a swing that hangs from 2.4-m-long chains. part a what is her maximum speed if she swings out to a 44 ∘ angle?

Answer 1

Answer;

= 3.63 m/s

Explanation;

• The speed reaches its maximum V when the swing arrives at its vertical position. At that very moment its kinetic energy is mV^2/2.
• In the initial position the potential energy is mgL(1-cosA), where L is the length, and A is the maximum angle.
• Considering that the potential energy is zero in the vertical position. Conservation of energy requires that ;

mV^2/2=mgL(1-cosA)

Thus;

V=sqrt[(2gL(1-cosA)]

= √[2 × 9.8 × 2.4 × (1 - cos 44)]

= √ 13.202

= 3.63 m/s