CapacityVolume is the amount of space an object occupies.Capacity is how much an object can hold.Capacity is often measured in litres (L or mL or KL or ML or GL)

1cm3 = 1mL 1m3 = 1KL (or 1000L)

1L of water weighs 1Kg1KL of water weighs 1T

mL L KL ML GL

×1000×1000×1000×1000

÷1000 ÷1000 ÷1000 ÷1000

Example 1Find the capacity of a Coke can with radius 3·1cm and a height of 12·5cm.

V = πr2h = π × 3·12 × 12·5 = 377·4 cm3

= 377.7 mL

Example 2Calculate the capacity of the swimming pool below in KL.

5m

9m

2m

6mV = AHYou may want to calculate the area first

A = ½(a + b)h = ½ × (5 + 9) × 2 = 14

V = AH = 14 × 6 = 84m3

= 84KL

Example 3A timber box is made with wood 1cm thick. If the outside dimensions of the box are 8cm by 15cm by 10cm,a) What is the volume of the box?b) What are the internal dimensions of the box?c) What is the capacity of the box?d) What is the volume of timber in the box?

a) V = LBH = 8 × 15 × 10 = 1200 cm3

b) 6cm by 13cm by 8cm

c) Capacity = LBH = 6 × 13 × 8 = 624 cm3

d) Timber = Volume – Capacity = 1200 – 624 = 576cm3

Today’s workExercise 6G page 216Q1, 3, 5, 7, 9, 11, 13