Chapter 1: Using apparatus
m/g
2.1
72.1
2.9
95.8
3.8
121.8
4.6
144.1
5.6
173.9
6.4
196.2
density of water (e.g. temperature), and consider whether these factors account for any discrepancy.
Sample results Table 1.2 provides sample results learners may obtain in the investigation. d = 6.6 cm (using metre rule) = 6.612 cm (using digital callipers) Mass of beaker = 99.0 g
Table 1.1 • If a learner needs to redraw their graph, supply a graph grid of identical size (24 cm × 16 cm) to the one in the workbook. Learners can insert the new grid in the appropriate place in the workbook.
Answers to the workbook questions (using the sample results) a
Balance reading / g
m/g
2.1
167.1
68.1
3.1
195.6
96.6
4.1
250.4
151.4
5.7
281.2
182.2
6.7
320.8
221.8
7.8
357.7
258.7
M PL
Learners should consider how close their values are to the accepted value for the density of water. They should research factors that may affect the value of the
h / cm
E
h / cm
See Table 1.2.
Table 1.2
d Gradient = 33.04 ρπd 2h e m = ρV so m = 4 f Proof
4 × 33.04 g d = 6.6 cm so ρ = π × 6.62 = 0.966 g cm−3
b, c See Figure 1.1.
h Advantages of callipers:
• able to measure the inside diameter of the beaker
300
SA
• more certain of measuring the maximum distance between opposite sides of the beaker.
250
200
m/g
150
100
50
2
3
4
5 h / cm
6
7
8
Figure 1.1 Original material © Cambridge University Press
3