A cone and sphere have equal volumes and radii of equal length. If the height of the cone is 36 centimeters, then what is the length of the radius of each shape in centimeters?
Q. A cone and sphere have equal volumes and radii of equal length. If the height of the cone is 36 centimeters, then what is the length of the radius of each shape in centimeters?
Write Formulas: The volume of a cone is given by the formula Vcone=31πr2h, where r is the radius and h is the height. The volume of a sphere is given by the formula Vsphere=34πr3. Since the volumes are equal, we can set the two formulas equal to each other and solve for r.
Set Equal: Set the volume of the cone equal to the volume of the sphere:31πr2h=34πr3.
Substitute Height: Substitute the given height h=36 cm into the equation:31πr2×36=34πr3.
Simplify Equation: Simplify the equation by multiplying out the constants:12πr2=4πr3.
Isolate Radius: Divide both sides of the equation by 4π to isolate r on one side:3r2=r3.
Solve for Radius: Divide both sides of the equation by r2, assuming r=0:3=r.
Final Result: We find that the radius r is 3 centimeters.
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