Solution:
 the boll, Â
y = Vo t + ½ g t² Â
y = 18 t + ½ (-9.8) t² Â
and the second one, Â
y = Vo t + ½ g t² Â
y = 30(t – 0.735) + ½ (-9.8)(t - 1.0.735)² Â
the stone and the ball will pass each other if, Â
y = y Â
18 t + ½ (-9.8) t² = 30(t – 0.73) + ½ (-9.8)(t - .0.73)² Â
t = 1.8196 sec Â
y = 18 t + ½ (-9.8) t² Â
y = 18(1.8196) + ½ (-9.8)(1.8196)² Â
y = 16.5292 m above initial point
Thus, this the required solution.
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