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A large dump truck will empty its full load of stone onto a small plot of land for storage. The rock forms a cone that is 9 feet tall. The truck holds 144 cubic feet of stone. What is the area of the circular base of the pile of stones?

Verified Answer :

Volume of a cone = (1/3) Area of Base height
144 * 3 / 9 = Area of Base
Area of the Base = 48



Answer:

48 square feet.

Step-by-step explanation:

A large dump truck will empty its full load of stone .

Those rock forms a cone.

Height of cone = 9 feet

The truck holds 144 cubic feet of stone.

So, amount of stone truck holds = Volume of cone

Formula of volume of cone = \(\frac{1}{3} \pi r^{2} h\)

Where \(\pi r^{2} = \text{Area of base }\)

           \(h= height\)

So, volume of cone formed  = \(\frac{1}{3}\times\text{Area of base}\times 9\)

Since we know that amount of stone truck holds = Volume of cone formed

\(144=\frac{1}{3}\times\text{Area of circular base}\times 9\)

\(144\times 3=\text{Area of base}\times 9\)

\(432=\text{Area of circular base}\times 9\)

\(\frac{432}{9}=\text{Area of circular base}\)

\(48=\text{Area of circular base}\)

Thus the area of the circular base is 48 square feet.