Kartik has three solid objects — a cone, a hemisphere, and a cylinder. All three have the same base radius and the same height. He completely immerses each solid in a bucket full of water. What is the ratio of the volumes of the cylinder : cone : hemisphere?
Explanation
To find the ratio of the volumes, we utilize the standard geometric volume formulas for each shape. Let r be the radius and h be the height of the objects. Because the objects have the same radius and height, we define h=r for these calculations.
Step 1: Define Volume Formulas
Volume of the Cylinder (Vcyl):
Vcyl=πr2h=πr2(r)=πr3
Volume of the Cone (Vcone):
Vcone=31πr2h=31πr2(r)=31πr3
Volume of the Hemisphere (Vhemi):
Vhemi=32πr3
Step 2: Calculate the Ratio
We need the ratio of Cylinder : Cone : Hemisphere:
Ratio=Vcyl:Vcone:Vhemi
Substituting the formulas:
Ratio=πr3:31πr3:32πr3
By dividing each term by 31πr3, we simplify the ratio:
Ratio=3:1:2
Correct Answer:
The ratio of the volumes of the cylinder, cone, and hemisphere is 3:1:2, which corresponds to option 2.