BASIC PHYSICS AND MATERIALS
(12PHF110)
January 2013
3 hours
______________________________________________________________________________
SECTION A contains 40 multiple choice questions, which should be answered on the examination
paper. Use a pencil (so that you can erase your answer if you change your mind). Do not mark
more than one box for each question.
There are FOUR alternative answers for each question. Select the correct answer by filling in the
appropriate bubble for questions ONE to FORTY. Each question carries the same mark. No marks
will be awarded for a question if more than one answer is selected. No marks will be deducted for
an incorrect answer. Section A is worth 40 marks.
SECTION B – answer ONE question – Section B is worth 20 marks
SECTION C – answer ONE question – Section C is worth 20 marks.
SECTION D – answer ONE question – Section D is worth 20 marks.
Any calculator from the University’s approved list may be used.
________
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SECTION B
Answer ONE question from this section.
1 (a)
Explain what is meant by ionic bonding using the elements potassium and chlorine and
their electronic structure schematics.
[4 marks]
(b)
Compare and contrast the two types of secondary bonding that occur in materials.
[4 marks]
(c)
Describe the electronic structure of the element neon and explain why the electronic
structure of an element affects its chemical reactivity.
[2 marks]
(d)
Using the example of Sodium and its bonding nature, explain why metals have high
electronic conductivity.
[4 marks]
(e)
Indicate four major factors that determine the properties of materials.
[4 marks]
(f)
Define ‘Unit Cell’ of a crystallographic structure.
[2 marks]
Define the terms; ductility, toughness and hardness.
[6 marks]
2 (a)
(b)
Zirconia can be used as a thermal barrier coating on gas turbine blades. What properties
does this ceramic possess which make it ideal for this application?
[4 marks]
(c)
Sketch the structures of the polymers; polyethylene and polyvinyl chloride and give one
use for each.
[4 marks]
(d)
Compare the advantages and disadvantages of SEM and TEM for the analysis of
materials.
[6 marks]
Continued …
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SECTION C
Answer ONE question from this section.
3. (a) The length of a metallic rectangular plate is L=(4.0±0.4) cm and its width is W=(30±3)
mm, estimate the area (in cm2) of the plate.
[5 marks]
(b) Comparing the units in the left and right hand-sides of the two equations, explain which
one can be correct and which one cannot be correct:
T=2𝜋[gR]1/2 and T=2𝜋[R/g]1/2 where g is the gravitational acceleration, R is the Earth
radius and T is the period of a satellite orbithe time it takes to complete one full orbit
around the Earth).
[5 marks]
(c)
Calculate resistance on the following circuit
ammeter A.
(figure Q3) and the current through the
Figure Q3
(Points a, b and c are added for your convenience as reference points).
[6 marks]
(d) We have 5 measurements of the radius of a ring: r1=1.0 cm, r2=1.5 cm, r3=1.2 cm, r4=1.4
cm, r5=1.4 cm. Determine the radius mean as well as 𝜎n-1 and standard error. [4 marks]
4. (a) Consider a circuit made of three capacitors (figure Q4(a)). Each capacitor has circular
parallel plates with radius r=0.5 cm. The plates are separated by a dielectric material of
relative permittivity 𝜀 r=2.0. The thickness of the first capacitor is d1=0.1 mm, while the
thickness of the second and the third capacitors are d2=0.2 mm; 𝜀 0=8.85x10-12 Fm-1.
Calculate:
(i)
Capacitances of the first (C1), second (C2) and third (C3) capacitors. [5 marks]
(ii)
Charges stored on capacitors C2 and C3 when the switch is connected to the
3V battery as shown in the left figure.
[5 marks]
(iii)
Charges stored on each capacitor when switch is reconnected to the capacitor
C1 (as in the right figure) after capacitors C2 and C3 are fully charged as
described in the previous problem.
[5 marks]
Figure Q4(a)
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(b) Calculate the effective capacitance of the network shown in figure Q4(b) if capacitance of
all capacitors are the same and equal to 1nF, that is C1=C2=C3=1.0nF.
[5 marks]
Figure Q4(b)
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SECTION D
Answer ONE question from this section.
5. (a) Dr Dann is playing in the annual staff-student cricket game. She throws the ball, which
has a mass of 150g, vertically upwards with a speed of 10 ms-1. What is the charge in
Potential Energy of the ball and its Kinetic Energy at its maximum height?
What is the change in the balls’ Potential Energy and its Kinetic Energy at half the
maximum height?
[7 marks]
(b) Dr Dann now accurately passes the ball to another player by throwing it at an angle of 300
to the horizontal at a speed of 20 ms-1. Calculate the distance to the other player.
[6 marks]
(c)
Whilst batting the ball is delivered to her at a speed of 50 ms-1. Assuming she strikes the
ball such that it leaves the bat at 60 ms-1 and that the contact time between bat and ball is
0.005 seconds, calculate the average force applied by the bat to the ball.
Take g=10 ms-2 and ignore air resistance.
[7 marks]
6. (a) Taking the acceleration due to gravity at the Earth’s surface to be 9.8 ms-2 and the mean
radius of the Earth as 6.4 x 106 m show that the mass of the Earth is 6 x 1024 kg.
[6 marks]
(b) The relative masses of the Earth and the Moon are 81:1 and the Moon has a radius of
1.74 x 106 m. Calculate the acceleration due to gravity on the Moon’s surface.
[6 marks]
(c)
A moon of Jupiter has a circular orbit around the planet with a period of 3.5 days and a
radius of 6.8 x 108 m. Our moon orbits the Earth with a period of 27 days at an average
distance of 3.9 x 108 m. Calculate the mass of Jupiter.
G = 6.7 x 10-11 Nm2kg-2.
[8 marks]
G.M.Swallowe, S. Saveliev, B. Vaidhyanathan, M Jepson.
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