Question

Donna is making candles in the shape of a cylinder. She needs to determine how many cubiccentimeters of wax she needs.Use the button or 3.14 in your computation. Round your answers to the nearest tenth as needed.If the radius of each candle is 5 cm and the height of each candle is 12 cm(a) How much wax is needed for one candle?cubic cm*(b) How much wax is needed for 100 candles?cubic cm

Answer 1

From the attached picture we can see that

The candle has shaped like a cylinder, and the amount of wax used is the volume of the cylinder

The rule of the volume of the cylinder is

$V=\pi r^2h$

r is the radius of its base

h is the height

Since the radius is 5 cm, then

r = 5

Since the height is 12 cm

h = 12

Use pi = 3.14

Substitute them in the rule above

$\begin{gathered} V=3.14\times(5^2)\times12 \\ V=3.14\times25\times12 \\ V=942\text{ cm}^3 \end{gathered}$

a)

It needs 942 cubic cm of wax to make one candle

To find the amount of wax to make 100 candles, multiply the answer of A by 100

$\begin{gathered} V=100\times942 \\ V=94200\text{ cm}^3 \end{gathered}$

b)

It needs 94200 cubic cm of wax to make 100 candles