Measuring Volume

What is volume?

• volume – the amount of space something fills– the volume of solids are commonly measured in

cubic centimetres (cm3) or cubic meters (m3)– the volume of liquids (or gases) are often

measured in litres (l) or millilitres (ml)• 1 ml = 1 cm3

• 1,000 ml = 1 litre

Finding the Volume of a Regular Solid

• regular solid – an object that has a structure that follows a set pattern, such that it has set angles (90 degrees for example) between its edges and faces

• the volume of regular solids with edges and faces that are square (such as a cube or a rectangular solid) is found by multiplying the height by the length by the width

Finding the Volume of a Regular Solid

10 cm

10 cm

10 cm

Volume of this cube = 10 cm x 10 cm x 10 cm = 1,000 cm3

Volume = height x length x width

Finding the Volume of a Regular Solid

4 cm

2 cm 10 cm

Volume of this rectangular solid = 4 cm x 2 cm x 10 cm = 80 cm3

Other Common Regular Solids

• pyramid• cylinder• cone

Finding the Volume of a Liquid

• you can find the volume of a liquid by pouring it into a measuring cylinder or measuring cup

• read the volume from the scale by keeping your eye at the level of the water and reading the lower level of the water (called the meniscus)

Finding the Volume of a Liquid

• it is important that the measuring cylinder is on a flat, level surface

Finding the Volume of an Irregular Solid

• irregular solid – an object that does not have straight edges or set angles– example: stone

Finding the Volume of an Irregular Solid• we can find the volume of an irregular solid

by using our knowledge of volume of a liquid• first, place enough water in a graduated

cylinder to cover the object and make a reading of the volume

• next, place the object in the cylinder• read the new level of the water• the volume of the object by subtracting the

first volume reading from the second volume reading

Finding the Volume of an Irregular Solid• example:– first reading: 200 ml– second reading: 260 ml– volume = second reading –

first reading– volume = 260 ml – 200 ml– volume = 60 ml

What you have learnedCopy and complete these sentences using these

key words (cubic centimetre, cubic metre, irregular, millilitres, regular, volume):

An object’s is the amount of space it fillsup. Two units of volume are and . Liquid volumes are

oftenmeasured in litres or . The volume of a solid is found by multiplying its height bythe length by the width. The volume of an solid can be found by measuring the volume ofwater it displaces.