Question

About how much cardboard is needed to make the inner tube for a roll of paper if the
tube has a diameter of 4.5 cm and is 24 cm long?

Answer 1

Answer:

$A=339.42\ cm^2$

Step-by-step explanation:

The diameter of the roll of paper, d = 4.5 cm

Radius, r = 2.25 cm

Height of the roll of papaer, h = 24 cm

We need to find how much is needed to make the inner tube for a roll of paper. The surface area of a cylinder for inner tube is given by :

$A=2\pi r h\\\\=2\times \dfrac{22}{7}\times 2.25\times 24\\\\=339.42\ cm^2$

So, the required area is $339.42\ cm^2$.