Question

A 20 kg child is on a swing that hangs from 2.6-m-long chains. What is her maximum speed if she swings out to a 46 angle?

Answer 1

Step-by-step explanation:

Here potential energy lost = mgh

h = L ( 1 - cos 46 ) where L is length of rope

= 2.6 x ( 1 - cos 46 )

PE lost = 20 x 9.8 x 2.6 ( 1 - cos 46 )

= 155.6 J

gain of kinetic energy = loss of PE

1/2 m v² = 155.6

.5 x 20 x v² = 155.6

v² = 15.56

v = 3.94 m /s