Ollscoil na hÉireann Gaillimh
National University of Ireland Galway
Semester I Examinations, 2017/2018
Exam Code(s)
Exam(s)
1BMS1, 1BO1, 1BPC1, 1BPT1, 1BS1, 1EH1, 1EM1, 1MR1,
1OA1, 1OS1, 0MB3
1st Science
Foundation Medical
Module Codes
PH101, PH1101
Module(s)
Physics
Paper No.
Repeat Paper
Paper I
___________
External Examiner(s)
Special Paper ____________
Prof. Malcolm Sperrin
Dr Eamonn Cunningham
Dr Gerard O’Connor
*Dr Ray Butler
*Dr Niall Colgan
*Dr Gary Gillanders
*Dr Mark Lang
Internal Examiner(s)
Instructions:
Answer Question 1 (30 marks), and TWO other questions (20 marks
each). The total marks for the paper are 70.
Note: You should state the correct units for all numerical answers.
Some physical constants and data are listed at the end of the paper.
Duration
Number of Pages
Discipline(s)
TWO HOURS
6
School of Physics
Requirements:
Release in Exam Venue
Yes
MCQ
Yes
Handout
Statistical/ Log Tables
Cambridge Tables
Graph Paper
Log Graph Paper
Other Materials
Graphic material in colour
None
State Examinations Commission Formulae and Tables
None
None
None
None
Yes
No
X
X
No
No
Page 1 of 6
X
Q.1
Compulsory question, answer all parts. [2 marks for each part].
a) How many cubic millimetres are there in one cubic metre?
b) Indicate which of the following are scalars and which are vectors: displacement,
distance, torque, pressure.
c) A runner increases their velocity from 5.2 m s−1 to 7.8 m s−1 in 4.0 s. Calculate their
acceleration.
d) A train, with an initial velocity of 15 m s−1 along a straight track, accelerates at a
constant 0.25 m s−2. Determine how far it travels before reaching a velocity of
20 m s−1.
e) A smooth slope makes an angle of 65o to the horizontal. Determine the acceleration
due to gravity down the slope.
f) A 20-kg box sits on a flat surface. The coefficient of static friction is 0.73. Calculate
the maximum static friction.
g) A wheel has a diameter of 60 cm. It rotates 4.5 times per second. Calculate the speed
of a point on the rim.
h) A proton has a velocity of 6.3×104 m s−1. Determine its kinetic energy.
i) An electron has a velocity of 3.0×105 m s−1. Calculate its momentum.
j) A metre stick has a mass of 190 grammes. It is suspended from its 38-cm mark.
Determine where you would have to hang a 150-gramme mass in order to balance the
metre stick.
k) An object of mass 120 grammes is suspended from a helical spring. The spring
constant is 8.5 N m−1. Calculate the period with which the object will oscillate up and
down.
l) A brass bar is 1.2 m long. It is heated up from an initial temperature of 10oC to a final
temperature of 75oC. Determine the increase in the length of the bar.
m) 11.7 kJ of heat energy is transferred to a 1.5-kg object. The temperature of the object
increases from 15oC to 35oC. Determine the specific heat capacity of the object and
identify the material it is made from.
n) The Sun has a surface temperature of 5800 K. Calculate the energy radiated per
second by one square metre of the Sun’s surface.
o) A flask has a volume of 4.5×10−3 m3 and contains a gas at a pressure of 2.8×105 Pa
and a temperature of 320 K. Calculate the number of moles of the gas present.
Page 2 of 6
Answer all parts
(a) Define what are meant by the following terms: displacement, velocity,
acceleration.
[3 marks]
[2 marks]
(b) Write down the four kinematic equations.
(c) An object of mass 3.7 kg starts at rest. It undergoes constant acceleration for an
integer number of seconds and then constant deceleration. Its displacement over a 10second time interval is illustrated in the graph below.
(i)
Use the value of the displacement after 4.0 s to determine the acceleration in the
initial phase.
[3 marks]
(ii) Using your answer from part (i) above, calculate the expected displacement of
the object after 5.0 s and 6.0 s. Comment on your answers. Explain when the
deceleration phase starts.
[4 marks]
(iii) Determine the deceleration in latter phase of the motion as accurately as you
can.
[4 marks]
(iv) Determine how much work has been done on the object over the 10-second
period.
[4 marks]
15
14
13
12
11
10
Displacement (m)
Q2.
9
8
7
6
5
4
3
2
1
0
0
1
2
3
4
5
6
Time (s)
Page 3 of 6
7
8
9
10
11
Q3.
Answer all parts
(a) Write the formula for Newton’s universal law of gravity, explaining all terms used.
[2 marks]
(b) Explain what is meant by centripetal force.
[2 marks]
(c) Derive a formula for the relationship between the period of a satellite and the radius of
its orbit.
[4 marks]
(d) The moon Triton orbits the planet Neptune every 5.88 days with an orbital radius of
3.55×105 km. Although Neptune is a gas giant we can still identify a “surface” at a
distance of 2.48×104 km from the centre.
(i)
Calculate the mass of Neptune.
(ii) Calculate the average density of Neptune.
[4 marks]
[3 marks]
(iii) The tiny inner moon Naiad orbits Neptune in just 423 minutes. Determine how
close this is to the planet’s surface.
[5 marks]
Q.4
Answer all parts
(a) Define what are meant by the terms: force and pressure. State the SI unit in which
each is measured.
[3 marks]
(b) Derive an expression for the pressure as a function of depth in a fluid. [4 marks]
(c) Determine the total pressure at the bottom of a lake which is 15.0 m deep.
[3 marks]
[2 marks]
(d) State Pascal’s principle.
(e) A hydraulic system consists of a cylindrical input piston of radius 2.5 cm. The
cylindrical output piston has a radius of 30 cm and a length of 90 cm and is made of
steel. It is located at a height h = 1.50 m above the input piston as shown in the
diagram below (which is not drawn to scale). The hydraulic oil has a relative density
of 0.80.
(i) Calculate the mass of the output
piston.
[2 marks]
(ii) Determine the pressure on the input
piston due solely to the column of
hydraulic oil.
[1 mark]
(ii) Determine what force is required on
the input piston to balance an 800-kg
object on top of the output piston.
[5 marks]
Page 4 of 6
Q.5
Answer all parts
(a) Briefly explain what are meant by the terms heat and temperature and state the SI
unit in which each is measured.
[3 marks]
(b) Briefly describe three methods by which heat may be transferred from one location
to another. In each case give one example.
[6 marks]
(c) A room with very well insulated walls, floor and roof has one window which has
dimensions 85 cm × 55 cm. The window glass is 0.50 mm thick and has a thermal
conductivity of 0.75 W m−1 K−1. The room is maintained at the temperature 18oC
using a 1.8 kW electric heater.
(i) Calculate the U-value for the window.
[2 marks]
(ii) Determine the outside temperature.
[4 marks]
(d) Write half a page about any physics related topic that has been in the news over the
last year.
[5 marks]
Page 5 of 6
PHYSICAL CONSTANTS and DATA
Absolute zero of temperature, 0 K
Acceleration due to gravity, g
Atomic mass unit, 1 u
Atomic mass of copper
Avogadro's number, NA
Boiling point of nitrogen
Boltzmann's constant, k
Coefficients of linear
 brass
thermal expansion of
 steel
Density of air at STP (0 oC, 1 atm)
Densities of
 copper
 lead
 mercury
 steel
 water
Distance (mean) Earth to Sun
Distance (mean) Earth to Moon
Electron volt, 1 eV
Electronic charge, e
Gas constant, R
Gravitational constant, G
Mass of the electron, me
Mass of the neutron, mn
Mass of the proton, mp
Mass of the Earth
Mass of the Moon
Mass of the Sun
Melting points of
 lead
 mercury
Permeability of vacuum, µo
Permittivity of vacuum, εo
k = 1/(4πεo)
Planck's constant, h
Radius of the Earth
Radius of the Moon
Radius of the Sun
Refractive indices of  glass
 water
Resistivity of nichrome
Specific heat
 copper
capacity of
 lead
 water
 ice
Specific latent heats
 lead
of fusion of
 water
Specific latent heats
 nitrogen
of evaporation of
 water
Speed of light in vacuum, c
Speed of sound in air (15 oC)
Standard atmospheric pressure
Stefan’s Constant, σ
Thermal conductivities
 glass
of
 copper
Young's modulus for steel
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
–273 oC
9.81 m s–2
1.6606 ×10–27 kg
63.54 kg kmol–1
6.02 ×1023 mol–1
77 K
1.38 ×10–23 J K–1
18 ×10–6 K–1
12 ×10–6 K–1
1.28 kg m–3
8960 kg m–3
11350 kg m–3
13600 kg m–3
7800 kg m–3
1000 kg m–3
1.50 ×1011 m
3.84 ×108 m
1.60 ×10–19 J
1.60 ×10–19 C
8.314 J K–1 mol–1
6.67 ×10–11 N m2 kg–2
9.11 ×10–31 kg
1.6749 ×10–27 kg
1.6726 ×10–27 kg
5.98 ×1024 kg
7.35 ×1022 kg
1.99 ×1030 kg
328 OC
−39 OC
4π ×10–7 H m−1
8.85 ×10–12 F m–1
9.0 ×109 N m2 C–2
6.63 ×10–34 J s
6.38 ×106 m
1.74 ×106 m
7.0 × 108 m
1.50
1.33
1.0 ×10–6 Ω m
389 J kg–1 K–1
125 J kg–1 K–1
4180 J kg–1 K–1
2092 J kg–1 K–1
21 ×103 J kg–1
335 ×103 J kg–1
1.99 ×105 J kg–1
2.26 ×106 J kg–1
3.0 ×108 m s–1
340 m s–1
1.01 ×105 Pa
5.67 ×10−8 W m−2 K−4
0.9 W m–1 K–1
398 W m–1 K–1
2.1 ×1011 N m–2
Page 6 of 6