Answer to Question #5743 in Mechanics | Relativity for
A 38 kg child on a 1.4 m long swing is released
from rest when the swing supports make an
angle of 21.2 with the vertical.
The acceleration of gravity is 9.81 m/s2 .
a) What is the maximum potential energy
associated with the child?
Answer in units of J
Let's make following denominations:
α = 21.2° L = 1.4 m M = 38 kg
Now let's find the height a child moved up:
H = L*cosα = 1.4*cos(21.2) ≈ 1.3053 m.