The formula for the volume of a cone is V=(1/3)πr^2h. Plugging in what you know, you get (1/18)π=(1/3)π(1/3)^2(h). The radius is half the diameter 2/3 so it is 1/3. Simplifying, you get (1/18)π=(1/3)π(1/9)(h) which is (1/18)π=(1/27)π(h). Dividing both sides by (1/27)π, you get h=1.5ft.
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