Question:
The volume of a right circular cone with both diameter and height equal to h is 250/7 cm³.
What is the value of h?
Answer:
A. 5
Step-by-step explanation:
Given
Solid Shape: Cone
Volume = 250/7
Diameter = Height
Required
Find the height of the cone
Provided that the diameter (D) and the height (h) are equal; This implies that
D = h ------ (1)
Also, Diameter (D) = 2 * Radius (r)
D = 2r
Substitute 2r for D in (1)
2r = h
Multiply both sides by ½
½ * 2r = ½ * h
r = ½h
Volume of a cone is calculated by;
Volume = ⅓πr²h
⅓πr²h = 250/7
Substitute ½h for r
[tex]\frac{1}{3} * \pi * (\frac{1}{2}h)^2 * h = \frac{250}{7}[/tex]
Take π as 22/7, the expression becomes
[tex]\frac{1}{3} * \frac{22}{7} * (\frac{1}{2}h)^2 * h = \frac{250}{7}[/tex]
Open the bracket
[tex]\frac{1}{3} * \frac{22}{7} * \frac{1}{4}h^2 * h = \frac{250}{7}[/tex]
Multiply both sides by 7
[tex]7 * \frac{1}{3} * \frac{22}{7} * \frac{1}{4}h^2 * h = \frac{250}{7} * 7[/tex]
[tex]\frac{1}{3} * 22 * \frac{1}{4}h^2 * h = 250[/tex]
Multiply both sides by 3
[tex]3 * \frac{1}{3} * 22 * \frac{1}{4}h^2 * h = 250 * 3[/tex]
[tex]22 * \frac{1}{4}h^2 * h = 750[/tex]
Multiply both sides by 4
[tex]4 * 22 * \frac{1}{4}h^2 * h = 750 * 4[/tex]
[tex]22 * h^2 * h = 3000[/tex]
[tex]22 * h^3 = 3000[/tex]
Divide both sides by 22
[tex]h^3 = \frac{3000}{22}[/tex]
[tex]h^3 = 136.36[/tex]
Take cube root of both sides
[tex]h = \sqrt[3]{136.36}[/tex]
[tex]h = 5.15[/tex]
[tex]h = 5[/tex] (Approximated)
