Posted by Holly on Wednesday, March 21, 2012 at 9:21pm.
A 80 kg child sits in a swing suspended with 2.6 mlong ropes. The swing is held aside so that the ropes make an angle of 46 o with the vertical. Use conservation of energy to determine the speed the child will have at the bottom of the arc when she is let go.

PHYSICS PLEASE HELP  drwls, Wednesday, March 21, 2012 at 9:28pm
(M/2)Vmax^2 = M g L(1  cos46)
L(1 cos 46) is the maximum rise of the swing above the bottom position, where the velocity is Vmax
Vmax = sqrt[2 g L (1cos46)] 
PHYSICS PLEASE HELP  Holly, Wednesday, March 21, 2012 at 9:38pm
does 1cos46 represent L or is L part of that equation?

PHYSICS PLEASE HELP  drwls, Wednesday, March 21, 2012 at 11:15pm
L is the rope length, and is part of the equation. I already told you what
L*(1 cos 46) is .