Keli weighs 456 Newton and she is sitting on a playground swing that hand .5 meter above the ground. Tom pulls the swing back and releases it when the sweat is 1.25 meter above the ground.
a.) Determine how fast is Keli moving when the swing passes through its lowest position?
b.) If Keli moves through the lowest point at 2.2 m/s, find how much work was done on the swing by friction?