The formula for finding the volume of a cone is V =
1
3
πr2h. The volume of a cone is 300 cm3 and the height of the cone is 10 cm. What is the approximate radius of the cone?
A) 3 cm
B) 5 cm
C) 9 cm
D) 28 cm

Respuesta :

Answer:  The correct option is

(B) 5.35 cm.

Step-by-step explanation:  Given that the formula for the volume of a cone with radius r units and height h units is

[tex]V=\dfrac{1}{3}\pi r^2h.[/tex]

Also, given that the volume of a cone is 300 cm³ and the height of the cone is 10 cm.

We are to find the approximate radius of the cone.

From the given formula, we can write

[tex]V=\dfrac{1}{3}\pi r^2h\\\\\\\Rightarrow 300=\dfrac{1}{3}\times\dfrac{22}{7}\times r^2\times10\\\\\\\Rightarrow r^2=\dfrac{300\times3\times7}{220}\\\\\\\Rightarrow r^2=\dfrac{6300}{220}\\\\\\\Rightarrow r^2=28.63\\\\\Rightarrow r=\pm5.35~(approx.)\\\\\Rightarrow r=\pm5[/tex]

Since the radius of the cone cannot be negative, so r = 5 am.

Thus, the required approximate radius of the cone is 5 cm.

Option (B) is CORRECT.

Answer:

Option B) 5 cm

Step-by-step explanation:

We are given the following information in question:

Volume of cone =

[tex]\displaystyle\frac{1}{3}\pi r^2h[/tex]

The volume of a cone is 300 cm cube and the height of the cone is 10 cm.

Putting the values in above equation:

[tex]\displaystyle\frac{1}{3}\pi r^2h = 300\\\\r^2 = \frac{330\times 3}{\pi \times 10} = \frac{330\times 3}{3.14 \times 10} = 31.5286\\\\r = 5.615 \approx 5[/tex]

Hence, the approximate radius of the cone is 5 cm.