You are provided with a uniform metre rule of mass, M indicated on its reverse side, a knife-edge, a graduated measuring cylinder of known mass, \(M_1\) marked on it and other necessary apparatus.
Read and record with values of M and \(m_1\).
Balance the metre rule horizontally on the knife edge. Read and record the balance point as G.
Tie a loop of thread around the neck of the measuring cylinder.
Fill the cylinder with the sand provided to the 2cm\(^{3}\) mark. Record the volume, V, of the sand.
Hang the cylinder at the 2 cm mark of the metre rule and adjust the position of the knife edge until the rule balances horizontally.
Read and record the new balance position K.
Determine the value of e and f.
Determine the mass, \(m_2\), of the sand in the measuring cylinder. Hint: \(m_2\) = (\(\frac{\text {M x f}}{e}\)) - \(m_1\).
Repeat the procedure by filling the measuring cylinder to the mark V = 4,6,8 and 10 cm\(^{3}\). In each case, ensure that the measuring cylinder is kept constant at the 2 cm mark on the metre rule.
Tabulate your readings.
Plot a graph with \(m_2\) on the vertical axis and V on the horizontal axis.
Determine the slope, s, of the graph.
State two precautions taken to ensure accurate results.
(b)i. Determine the mass of 7.5 cm\(^{3}\) of the sand using your graph.
ii. A gold coin of mass 102.0 g has a uniform cross-sectional area of 10.0 cm\(^{2}\). Calculate its thickness. [Density of gold=19.3 g cm\(^{-3}\)]
Verified Correct Answer: .
Physical Principles & Numerical Solution
volume of sand v/cm\(^{3}\)
k/cm
\(\theta\)=(k-p)/cm
f=(G-K)/cm
\(m_2\)=\(\frac{mxf}{e}\)-\(m_1\)
2
43.5
41.5
6.9
1.614
4
42.7
40.7
7.7
3.443
6
41.9
39.9
8.5
6.372
8
40.1
39.1
9.3
9.416
10
40.4
38.4
10.0
12.178
Slope = \(\frac{\bigtriangleup {m}_{2}}{\bigtriangleup {v}}\)
= \(\frac{12-8-4}{10.4-4.4} = \frac{(8.8)9}{(6)cm^{3}}\)
= 1.4679/cm\(^{3}\)
Observation;
Mass of uniform metre rule m--> 130g
Mass of graduated measuring cylinder \(m_1\) --20g
Balance point G = 50.4cm
PRECAUTIONS; i
Avoided draught
Avoided parallax error in reading metre rule/ measuring cylinder
Knife-edge firmly clamped
Avoided measuring cylinder from resting on/touching the table
Repeated readings are shown on the table
(b)i. 7.5cm\(^{3}\) correctly shown on graph \(m_2\) = 8.4g
ii. V = \(\frac {\text{Mass}} {\text{Density}} = \frac{102.0}{19.3}\) = 5.28
Volume = thickness x area
thickness = \(\frac {\text{Volume}}{\text{Area}} = \frac{5.28}{10}\)
OR
t = \(\frac{m}{A} = \frac{102}{19.3 \times 10}\) = 0.528cm
Source: Myschool Past Questions Archive (Record #59982)