Question

A water bottle in the shape of a cylinder holds 1 litre of water when it's full. It's height is 15cm. Work out the radius of the water bottle (1litre=1000cm3)

Answer 1

Answer: 4.6 cm

Step-by-step explanation:

Given

Volume of water $V=1\ L\ \text{or}\ 1000\ cm^3$

The height of the water is $h=15\ cm$

The volume of the cylinder is $\pi r^2h$

Insert the values

$\Rightarrow 1000=\pi (r^2)15\\\\\Rightarrow r^2=\dfrac{1000}{3.142\times 15}\\\\\Rightarrow r^2=\dfrac{1000}{47.13}\\\\\Rightarrow r^2=21.217\\\Rightarrow r=4.6\ cm$