A bridge construction company is putting cone-shaped tops on each bridge support to discourage birds from roosting. Each cone will be filled with cement. How much cement will they have to put in each cone? (Use [tex]\pi = 3.14[/tex].)

A. 314 cm³
B. [tex]271.2 \, \text{cm}^3[/tex]
C. 942 cm³
D. [tex]282.6 \, \text{cm}^3[/tex]



Answer :

To determine how much cement is needed to fill each cone-shaped top placed on the bridge supports, we need to calculate the volume of one cone. The formula for the volume [tex]\( V \)[/tex] of a cone is given by:

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

where:
- [tex]\( \pi \)[/tex] (pi) is approximately 3.14,
- [tex]\( r \)[/tex] is the radius of the base of the cone,
- [tex]\( h \)[/tex] is the height of the cone.

Assuming we have the values for radius [tex]\( r \)[/tex] and height [tex]\( h \)[/tex] as follows:
- Radius [tex]\( r = 5 \, \text{cm} \)[/tex],
- Height [tex]\( h = 9 \, \text{cm} \)[/tex].

Let's now substitute these values into the volume formula:

[tex]\[ V = \frac{1}{3} \times 3.14 \times (5)^2 \times 9 \][/tex]

First, calculate the square of the radius:

[tex]\[ 5^2 = 25 \][/tex]

Next, multiply this result by the height [tex]\( h \)[/tex] and [tex]\( \pi \)[/tex]:

[tex]\[ 25 \times 9 = 225 \][/tex]
[tex]\[ 225 \times 3.14 = 706.5 \][/tex]

Finally, multiply by [tex]\(\frac{1}{3}\)[/tex]:

[tex]\[ V = \frac{1}{3} \times 706.5 = 235.5 \, \text{cm}^3 \][/tex]

Therefore, the volume of the cement needed to fill each cone is approximately:

[tex]\[ 235.5 \, \text{cm}^3 \][/tex]

Given the options:
A) 314 cm³
B) 271.2 cm³
C) 942 cm³
D) 282.6 cm³

The result closest to our calculated volume is not exactly among the provided options, but the true answer obtained after calculation is:

[tex]\[ 235.5 \, \text{cm}^3 \][/tex]