1a. (i) Using the spring balance provided, determine the weight of an object of mass M = 5.0 g. Record this weight as W\(_1\).
(ii) Determine the weight of the object when completely immersed in water contained in a beaker as shown in the diagram. Record the weight as W\(_2\).
(iii) Determine the weight of the object when it is completely immersed in the liquid labelled "L". Record the weight as W\(_3\). Evaluate u = (W\(_1\) - W\(_2\)) and v = (W\(_1\) - W\(_3\)).
(iv) Repeat the procedure with the objects of masses M = 10, 15, 20, and 25 g. In each case, evaluate v = (W\(_1\) - W\(_3\)) on the vertical axis against u = (W\(_1\) - W\(_2\)) on the horizontal axis.
(v) Determine the slope, s, of the graph.
(vi) State two precautions taken to ensure accurate results.[21 marks]
bi. A piece of brass of mass 20.0 g is hung on a spring balance from a rigid support and completely immersed in kerosene of density 8.0 \times 10\(^2\) kgm\(^{-3}\). Determine the reading on the spring balance. [g = 10 ms\(^{-2}\), density of brass = 8.0 \times 10\(^3\) kgm\(^{-3}\)]
(Provide your answer with unit e.g 123.123 m)
bii. Archimedes' Principle and Law of Floatation [2 marks]
Attached Figure / Diagram
Verified Correct Answer: .
Physical Principles & Numerical Solution
1a. Tables of values
M(g)
W\(_1\)(g)
W\(_2\)(g)
W\(_3\)(g)
U = (W\(_1\) - W\(_2\)(g)
V = (W\(_1\) - W\(_3\)(g)
5.0
5.00
4.20
4.70
0.80
0.30
10.0
10.00
7.90
8.60
2.10
1.40
15.0
15.00
12.75
13.50
2.25
1.50
20.0
17.10
17.10
16.40
2.90
3.60
25.0
22.10
22.10
21.40
2.90
3.60
S = \(\frac{y_2 - y_1}{x_2 - x_1}\) = \(\frac{3 - 0.8}{2.8 - 1.4}\) = \(\frac{11}{7}\) = 1.57.
Precaution
(i) I carefully avoided parallax error while reading the scale of the spring balance to ensure accurate measurements.
(ii) I checked and accounted for any zero error on the spring balance before taking measurements.
(iii) I handled the liquid carefully to prevent any splashing, which could lead to loss of material or inaccurate readings.
(iv) I ensured that the object did not touch the bottom or sides of the beaker to avoid interference with the force readings.
(v) I thoroughly cleaned the object (mass) before dipping it into the liquid to prevent contamination or alteration of the liquid's properties.
bii) Law of Floatation: The law of floatation states that an object will float in a fluid if its weight is equal to the weight of the fluid it displaces. For a floating object, the weight of the object is balanced by the upward buoyant force.
Source: Myschool Past Questions Archive (Record #76565)