Newton’s second law of motion states that:
D.
A small object is attached to a string and is made to move in a horizontal circle.
Which of the following free-body diagrams correctly shows the forces that act on the object?
A.
A speedboat starts from rest and accelerates at 5.0 m s^{-2}. What is the velocity of the speedboat after it has travelled a distance of 10 m?
C.
An object moves is a circle at a constant speed of 6.0 m s^{-1}. The radius of the circle is 2.0 m. What is the angular speed of the object?
B.
The SI unit combination of energy density is:
B.
Two forces act on an object as shown on the diagram.
Which of the following vectors shows the direction of the net force acting on the object?
C.
A graph shows how the velocity of an object varies with time. What does the gradient of the graph represent?
B.
An object is moving at constant speed. Which graph shows the variation of E, its kinetic energy, with s, its displacement?
D.
A small sphere is falling through oil at constant speed.
Which of the following free-body diagrams correctly shows the forces that act on the sphere?
C.
A thermally isolated container has 10 kg of ice. The specific latent heat of fusion of ice is 0.336 MJ kg^{-1}. How much energy must be supplied to the ice to completely melt it, without changing its temperature?
C.
The resistance of an aluminium wire of length L and radius r is R. What will be the resistance when both the length and the radius are doubled?
A.
The density of a metal cube with side length L and mass M is \rho.
What is the density of a metal cube with side length \frac{L}{2} and mass \frac{M}{4}?
D.
Containers A and B contain the same substance at the same temperature. In container A the substance is in the gas state. In container B the substance is in the liquid state. The average kinetic energy of the molecules in container A is E_{A} and the average kinetic energy of the molecules in container B is E_{B}. What is true about E_{A} and E_{B}?
D.
A student wants to connect an ammeter and a voltmeter to measure the current through and the potential difference across a resistor. How should the ammeter and the voltmeter be connected to the resistor?
| Ammeter | Voltmeter | |
| A. | Series | Parallel |
| B. | Parallel | Series |
| C. | Series | Series |
| D. | Parallel | Parallel |
A.
Water is heated from 40 ^{o}C to 50 ^{o}C in a thermally isolated container. The total energy supplied to the water is 84000 J. The specific heat capacity of water is 4200 J kg^{-1} K^{-1}. What is the mass of the water?
C.
Which of the following is not an assumption of the kinetic model of ideal gases?
D.
The power supplied by a battery per unit current from the battery is a definition of:
B.
The rate of global warming will most likely be increased by:
D.
A monatomic real gas can behave very similarly to an ideal gas under certain conditions. Which of the following is one of these conditions?
A.
A temperature of 58 ^{o}C is equal to:
D.
A substance turns from a liquid into a solid. The temperature of the substance does not change during the process. Which of the following statements is true about the process?
B.
Which of the following lists three greenhouse gases?
B.
Which of the following shows colours of visible light in increasing order of wavelength?
C.
The frequency of a mass-spring system oscillating horizontally with simple harmonic motion (SHM) on the surface of planet X is f. The gravitational field strength at the surface of planet X is g_{X}. The mass-spring system is moved to the surface of planet Y where the gravitational field strength is g_{Y}. \frac{g_{X}}{g_{Y}}=\frac{1}{4}. What is the frequency at which the mass-spring system oscillates on the surface of planet Y?
B.
A pendulum oscillates with simple harmonic motion (SHM). The length of the pendulum is 10 m and the gravitational acceleration is 10 m s^{-2}.
What is the period of the pendulum?
B.
Two pulses travel towards each other as shown on the diagram.
Which one of the following diagrams shows a possible configuration when the two pulses meet?
C.
When a transverse wave travels through a medium, which of the following is true about the direction of propagation and the energy transfer of the wave in relation to the displacement of the medium?
| Direction of propagation | Direction of energy transfer | |
| A. | Perpendicular | Parallel |
| B. | Parallel | Parallel |
| C. | Parallel | Perpendicular |
| D. | Perpendicular | Perpendicular |
D.
The Doppler effect:
C.
Two identical waves meet and interfere constructively. The intensity of each wave is I and the amplitude of each wave is A. What are the intensity and the amplitude of the resultant wave?
| Intensity | Amplitude | |
| A. | 2I | 2A |
| B. | 4I | 4A |
| C. | 4I | 2A |
| D. | 2I | 4A |
C.
A restoring force acts on an object that performs simple harmonic motion (SHM) about a fixed point. What is correct about the direction of the restoring force and the direction of the object’s velocity?
C.
The distance between two adjacent nodes on a standing wave is 4 cm. What is the wavelength of the wave?
D.
Two parallel, straight wires carry currents in opposite directions as shown on the diagram.
Which of the following statements is correct about the wires?
A.
Phobos is one of the moons that orbits Mars. Newton’s universal law of gravitation can be applied to calculate the force between Phobos and Mars. Which one of the following conditions enables this calculation?
A.
One electronvolt is equivalent to:
D.
A proton is held at rest between two parallel, charged plates. The gravitational force acting on the proton is negligible.
In which direction will the proton move when released?
C.
A spaceship is orbiting a planet in a circular orbit at constant speed. Which of the following statements is true about the spaceship’s motion?
A.
Millikan’s oil drop experiment provides evidence for the
B.
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The average binding energy per nucleon versus nucleon number graph has a maximum. The region around this maximum:
A.
The half-life of a radioactive element is 1 day. The initial number of undecayed atoms in a pure sample of this element is 200.
How many undecayed atoms are there in the sample after 3 days?
B.
What is the main source of energy in stars?
A.
The existence of atomic energy levels is supported by:
A.
Which of the following properties is affected when a nucleus decays through gamma-decay?
D.
What part of the nuclear power plant conveys energy from the reactors to the turbines?
C.
A nuclide decays through beta-minus decay. What property of the nuclide remains unchanged as a result of this decay?
D.
Which of the following quantities can be directly determined from the emission spectrum of a star?
B.
The graph shows how the horizontal force exerted by a golf club on a golf ball varies with time. The mass of the golf ball is 46 grams. The golf ball is initially at rest.
a. Define impulse.
[1]
b. Show that the speed of the golf ball as it loses contact with the golf club is about 40 m s^{-1}.
[3]
c. Calculate the average force exerted by the golf club on the golf ball.
[1]
Impulse is change in momentum.
The area under the graph = \Delta p = \frac{1}{2}(10 \times 10^{-3})(350) = 1.75 N s
1.75 = (0.046)v
v = 38 \approx 40 m s^{-1}
Calculated answer must be given to at least 2 significant figures in order to earn the final mark.
F_{ave} = \frac{\Delta p}{\Delta t} = \frac{1.75}{10 \times 10^{-3}} = 175 N
A pulse is travelling on a string that has one end fixed to a wall.
When the pulse reaches the wall, it is reflected.
a. Sketch the pulse after it has been reflected at the wall.
[1]
The end of the string is vibrated vertically so that a transverse wave travels through the string. The time period of the vibrations is 1.62 s. The length of the string is 1.95 m.
b. Distinguish between a transverse and a longitudinal travelling wave.
[2]
c. Calculate the speed of the wave. Give your answer to an appropriate number of significant figures.
[3]
In a transverse wave the displacement of the medium is perpendicular to the direction of wave propagation/energy transfer.
In a longitudinal wave the displacement of the medium is parallel to the direction of wave propagation/energy transfer.
Wavelength of the wave: \lambda = \frac{1.95}{2.5} = 0.780 m
v = f \lambda = \frac{\lambda}{T} = \frac{0.780}{1.62} \approx 0.481 m s^{-1}
Answer must be given to 3 significant figures in order to earn final mark.
An expandable balloon is filled with a fixed mass of argon-40 gas. The pressure of the gas is maintained at 1.3 kPa. The graph shows how the volume of the gas varies with temperature.
a. State two assumptions of the kinetic model of an ideal gas.
[2]
b. Explain why argon-40 behaves as an ideal gas for temperatures between 20 \: ^{\circ}C and 70 \: ^{\circ}C.
[2]
c. Find the mass of the argon-40 gas in the balloon.
[2]
Any two of the following:
Gas molecules are considered tiny, point-like particles that have the same mass.
The volume of each molecule is negligible compared to the total volume of the gas.
Intermolecular forces between the particles are negligible.
The gas molecules only have kinetic energy.
All collisions that take place are elastic.
The duration of collisions is negligible compared to the time between collisions.
At any moment, the number of molecules moving in one direction is the same as the number of molecules moving in any other direction.
The effects of gravity are ignored.
If argon behaves as an ideal gas, then the ideal gas equation should work for this gas on the given temperature range. This means that at constant pressure \frac{V}{T} should be constant.
Let’s pick two points from the graph to show this:
\frac{15}{300} = 0.05
\frac{25}{500} = 0.05
This means that argon behaves as an ideal gas on the given temperature range.
n = \frac{(1.3 \times 10^{3})(15)}{(8.31)(300)} \approx 7.82 moles
The molar mass of argon-40 is 40 grams, so the mass of the gas in the container is (7.82)(40) \approx 313 \approx 310 grams
Gadolinium-149 \left ( _{\, \, \, 64}^{149}\textrm{Gd} \right ) decays into samarium-145 \left ( _{\, \, \, 62}^{145}\textrm{Sm} \right ) through alpha decay.
The following data is provided:
Binding energy per nucleon for samarium: 8.293 MeV
Binding energy per nucleon for helium: 7.073 MeV
Energy released during the decay: 4.827 \times 10^{-13} J
a. State what is meant by binding energy of a nucleus.
[1]
b. Calculate the binding energy per nucleon for gadolinium-149. Give your answer in MeV.
[3]
A pure sample of gadolinium-149 decays into samarium-145. After 46.4 days \frac{number\: of\: gadolinium\: nuclides}{number\: of\: samarium\: nuclides} \approx 0.0323.
c. Estimate the half-life of gadolinium-149.
[3]
The energy required to completely separate the nucleons of a nucleus.
OR
The energy released when a nucleus is formed from its nucleons.
Total binding energy of samarium and alpha-particle:
(145 \times 8.293) + (4 \times 7.073) = 1230.777 MeV
Converting the energy released into MeV:
\frac{4.827 \times 10^{-13}}{1.6 \times 10^{-19}} \approx 3.017 \times 10^{6} eV = 3.017 MeV
Binding energy per nucleon for gadolinium-149:
\frac{1230.777-3.017}{149} \approx 8.240 MeV
0.0323 \approx \frac{1}{31}
This means that \frac{1}{32} of the original number of gadolinium nuclides are still undecayed in the sample, therefore five half-lives have elapsed.
So the half-life of gadolinium is \frac{46.4}{5} = 9.28 days