A child with a weight of 220 N swings on a playground swing attached to 1.80 m long chains. What is the gravitational potential energy (in ]) of the child-earth system relative to the child's lowest position at the following times? (a) when the chains are horizontal (b) when the chains make an angle of 35.0 with respect to the vertical J (c) when the child is at his lowest position Supporting MaterialsWhile leaning out a window that is 6.5 m above the ground, you drop a 0.60 kg basketball to a friend at ground level. Your friend catches the ball at a height of 1.9 m above the ground. Determine the following. (a) the amount of work done (in ]) by the force of gravity on the ball (b) the gravitational potential energy (in J) of the ball-earth system, relative to the ground when it is released (c) the gravitational potential energy (in ]) of the ball-earth system, relative to the ground when it is caught (d) the ratio of the change (PE - PE) in the gravitational potential energy of the ball-earth system to the work done on the ball by the force of gravity APE W