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PLEASE HELP ME ANSWER THIS QUESTION?

PLEASE HELP ME ANSWER THIS QUESTION?-example-1
User Ken Yao
by
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1 Answer

7 votes
The proportion of radius will be the same with the proportion of the height. Make a comparison

\cfrac{h_(1)}{h_(2)}=\cfrac{r_(1)}{r_(2)}

Input the numbers

\cfrac{h_(1)}{h_(2)}=\cfrac{40}{16}

simplify the fraction, divide the numerator and denominator by 8

\cfrac{h_(1)}{h_(2)}=\cfrac{5}{2}

do cross multiplication
2h₁ = 5h₂
h₂ =
(2)/(5)h_(1)

General formula to find the volume
1/3 × π × r² × h = volume
In the case of the first cone
1/3 × π × 40² × h₁ = 1,875
1/3 × π × 1,600 × h₁ = 1,875
1/3 × π × h₁ =
(1,875)/(1,600)
save it, we'll use this expression later

In the case of the second cone
We know that h₂ =
(2)/(5)h_(1)
So the expression will be
1/3 × π × r₂² × h₂ = v₂
1/3 × π × 16² × h₂ = v₂
1/3 × π × 256 ×
(2)/(5)h_(1) = v₂
1/3 × π × h₁ ×
(256 * 2)/(5) = v₂
1/3 × π × h₁ ×
(512)/(5) = v₂

Use the expression we save, substitute 1/3 × π × h₁ with
(1,875)/(1,600)

(1,875)/(1,600) *(512)/(5) = v₂
120 = v₂

The volume of the second cone is 120 cm³
User Eternalmatt
by
6.1k points