Page 56 - Physics

Physics for Secondary Schools

3. Gently lower the stone into the water Solution
as shown in Figure 2.35 (b).
4. Read the fi nal volume of water V . Initial volume of water V = 65 cm 3
1
2
5. The difference between the fi nal and Final volume of water V = 81 cm 3
the initial volume gives the volume of 2
the stone. The volume of solid, V = V − V

Volume of the stone V s 2 1
s V = 81 cm − 65 cm = 16 cm 3
3
3
= final volume (V )−initial volume (V ) s
1
2
V =V −V . Therefore, the volume of the irregular
s
2
1
solid is 16 cm .
3
String Measuring the volume of an irregular
objects using a eureka can
If the object is too large to fi t into the
Final measuring cylinder, an alternative method
volume
is to use an overfl ow can commonly known
as the eureka can shown in Figure 2.36.
Increase
in This is a large can with an overfl ow spout
volume
near the top. In practice, the following steps
Initial are involved when using an overfl ow can to
volume
measure the volume of an irregular object.
1. Fill the eureka can with water up to
the level of the spout, as illustrated
(a) (b) in Figure 2.36.

Figure 2.35: Measuring the volume of an Eureka Can
irregular object
Spout
In the illustration,

V = 600 ml − 300 ml = 300 ml. Water
s
Beaker

Example 2.8

When an irregular solid object was Figure 2.36: Set up a Eureka Can
immersed in 65 cm of water, the water
3
level rose to 81 cm . What was the 2. Tie the irregular object with a string.
3
volume of the irregular solid object? 3. Gently lower the object into the
water using the string.

50
Student’s Book Form One

Physics Form 1 Final.indd 50 16/10/2024 20:55