7-51. A boy is playing with a rope tied to a tree near his favourite swimming hole (See the Figure). Initially the boy is stationary and the rope (of length 3.7 m) makes an angle of 48^o with the vertical. He then lifts his feet slightly and starts to swing freely. If air resistance is neglected, use conservation of energy to determine:
(a) his speed at the bottom of the swing
(b) the minimum height, relative to his initial position, to which he can swing.
 
 
 
 
 
 
 
 
 
 
 

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Where should the origin be chosen in this problem?
(A)   Where the motion starts, i.e. at 1 in the drawing.
(B)   At the bottom of the swing, i.e. at 2 in the drawing.
(C)   At the top of the rope.