Physics SL

Question 1 

Newton’s second law of motion states that:

1. The net force acting on a body is equal to the product of its mass and velocity.
2. When one body exerts a force on a second body, the second body simultaneously exerts a force equal in magnitude and opposite in direction on the first body.
3. The net force acting on a body is proportional to the momentum of the body.
4. The rate of change of momentum of a body is equal to the net force acting on the body.

Question 2 

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?

Question 3 

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?

1. 2.5 m s^{-1}
2. 5.0 m s^{-1}
3. 10 m s^{-1}
4. 50 m s^{-1}

Question 4 

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?

1. 1.5 rad s^{-1}
2. 3.0 rad s^{-1}
3. 12 rad s^{-1}
4. 24 rad s^{-1}

Question 5

The SI unit combination of energy density is:

1. J m^{3}
2. J m^{-3}
3. J kg
4. J kg^{-1}

Question 6 

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?

Question 7 

A graph shows how the velocity of an object varies with time. What does the gradient of the graph represent?

1. The displacement of the object
2. The acceleration of the object
3. The momentum of the object
4. It does not represent a physical quantity

Question 8 

An object is moving at constant speed. Which graph shows the variation of E, its kinetic energy, with s, its displacement?

Question 9 

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?

Question 10 

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? 

1. 0.0336 MJ
2. 0.336 MJ
3. 3.36 MJ
4. 33.6 MJ

Question 11 

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?

1. 0.5R
2. R
3. 2R
4. 4R

Question 12 

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}?

1. \frac{\rho}{4}
2. 4 \rho
3. \frac{\rho}{2}
4. 2 \rho

Question 13 

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}?   

1. Based on the information provided, the relationship between E_{A} and E_{B} cannot be determined.
2. E_{A}>E_{B}
3. E_{A}<E_{B}
4. E_{A}=E_{B}

Question 14 

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?

Question 15 

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?

1. 0.2 kg
2. 0.5 kg
3. 2.0 kg
4. 5.0 kg

Question 16 

Which of the following is not an assumption of the kinetic model of ideal gases?

1. The volume of each molecule is negligible compared to the total volume of the gas.
2. Intermolecular forces between the particles are negligible.
3. The duration of collisions is negligible compared to the time between collisions.
4. The change in the velocity of the molecules is negligible during collisions with the container wall.

Question 17 

The power supplied by a battery per unit current from the battery is a definition of:

1. Potential difference
2. Electromotive force
3. Internal resistance
4. Ohm’s law

Question 18

The rate of global warming will most likely be increased by:

1. replacing coal-based power stations by nuclear power stations.
2. reforestation.
3. using natural gas instead of oil.
4. decreasing the use of renewable energy sources.

Question 19 

A monatomic real gas can behave very similarly to an ideal gas under certain conditions. Which of the following is one of these conditions?

1. Low pressure
2. Low temperature
3. High pressure
4. High density

Question 20 

A temperature of 58 ^{o}C is equal to:

1. -215 K
2. 215 K
3. -331 K
4. 331 K

Question 21 

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?

1. Energy is supplied to the substance.
2. The total internal energy of the system decreases.
3. The kinetic energy of the molecules in the substance decreases.
4. The intermolecular potential energy of the substance is unchanged. 

Question 22 

Which of the following lists three greenhouse gases?

1. Carbon dioxide, methane, oxygen
2. Methane, water vapour, nitrous oxide
3. Water vapour, oxygen, carbon dioxide
4. Nitrous oxide, nitrogen, methane

Question 23 

Which of the following shows colours of visible light in increasing order of wavelength?

1. red, green, violet
2. green, red, violet
3. violet, green, red
4. violet, red, green

Question 24 

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?

1. \frac{f}{2}
2. f
3. 2f
4. 4f

Question 25 

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?

1. \pi 
2. 2\pi 
3. 4\pi 
4. 8\pi 

Question 26 

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?

Question 27 

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?

Question 28 

The Doppler effect:

1. Occurs for light waves only.
2. Occurs for sound waves only.
3. Occurs both for light waves and sound waves.
4. Occurs neither for light nor for sound waves.

Question 29 

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?

Question 30 

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?

1. Never opposite
2. Always opposite
3. Opposite for half of a period
4. Opposite for a quarter of a period.

Question 31 

The distance between two adjacent nodes on a standing wave is 4 cm. What is the wavelength of the wave?

1. 1 cm
2. 2 cm
3. 4 cm
4. 8 cm

Question 32 

Two parallel, straight wires carry currents in opposite directions as shown on the diagram.

Which of the following statements is correct about the wires?

1. The magnitude of the forces exerted by the wires on each other is the same. The forces are repulsive.
2. The magnitude of the forces exerted by the wires on each other is the same. The forces are attractive.
3. The force exerted by wire A on wire B is smaller than the force exerted by wire B on wire A. The force is repulsive.
4. The force exerted by wire A on wire B is smaller than the force exerted by wire B on wire A. The force is attractive.

Question 33 

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?

1. Phobos and Mars can be considered as point masses.
2. The distance between Phobos and Mars is large enough.
3. Phobos and Mars both have a large volume.
4. Phobos has a circular orbit around Mars.

Question 34 

One electronvolt is equivalent to:

1. 1.6 \times 10^{-19} N
2. 1.6 \times 10^{-19} W
3. 1.6 \times 10^{-19} V
4. 1.6 \times 10^{-19} J

Question 35 

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?

1. Left
2. Right
3. Downwards
4. Upwards

Question 36 

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?

1. The net force acting on the spaceship and the velocity of the spaceship are perpendicular.
2. The acceleration of the spaceship is zero.
3. There is no gravitational force acting on the spaceship.
4. The kinetic energy of the satellite increases as it orbits the planet.

Question 37 

Millikan’s oil drop experiment provides evidence for the

1. existence of electrons.
2. quantization of electric charge.
3. quantization of atomic energy levels.
4. existence of neutrinos.

Question 38 

The average binding energy per nucleon versus nucleon number graph has a maximum. The region around this maximum:

1. contains the most stable nuclides
2. contains nuclides that decay through alpha-decay.
3. contains nuclides that decay through beta-decay.
4. is where radioactive decay is most likely to occur.

Question 39 

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?

1. 0
2. 25
3. 50
4. 100

Question 40 

What is the main source of energy in stars?

1. Nuclear fusion
2. Nuclear fission
3. The burning of fossil fuels at high temperatures
4. Radioactive decay

Question 41 

The existence of atomic energy levels is supported by:

1. evidence from emission and absorption spectra.
2. the Rutherford-Geiger-Mardsen scattering experiment.
3. observations related to the wave nature of light.
4. the neutron-to-proton ratio of stable elements.

Question 42 

Which of the following properties is affected when a nucleus decays through gamma-decay?

1. The proton number of the nucleus
2. The charge of the nucleus
3. The neutron number of the nucleus
4. The energy state of the nucleus

Question 43

What part of the nuclear power plant conveys energy from the reactors to the turbines?

1. Control rods
2. Moderator
3. Heat exchanger
4. Reactor vessel

Question 44 

A nuclide decays through beta-minus decay. What property of the nuclide remains unchanged as a result of this decay? 

1. The atomic number.
2. The neutron number.
3. The charge of the nuclide.
4. The mass number.

Question 45

Which of the following quantities can be directly determined from the emission spectrum of a star?

1. Exact mass
2. Chemical composition
3. Luminosity
4. Apparent brightness

Question 2 

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]

Question 3 

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]

Question 4 

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]