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MYP 5- Practice for boards- DIY
IB Middle Years
Physics
Grade:
Year 5
Criteria:
A 27
Total:
100 points
Authors:
Pushkar Sathe, Shaji Poulose, Sonal Shrivastava, Vidya
Tilak, Sudesh Diwaniya, Aditya Dalal
B 23
C 25
D 25
Page 1 of 31
Criteria A
A student designed a model as shown in the picture below. Analyze the picture and answer the
questions.
Q 1.1
State and explain the principal that is being used in this model
A3
Teacher's Explanation
The principle being used in a water wheel conducting electricity is the conversion of potential energy
into kinetic energy and then into electrical energy.
1. Potential Energy: Water stored at a higher elevation possesses potential energy due to its
position in the Earth's gravitational field.
2. Kinetic Energy: As the water flows downhill and strikes the blades of the water wheel, its
potential energy is converted into kinetic energy (energy of motion). The force of the moving
water causes the wheel to rotate.
3. Mechanical Energy: The rotating water wheel transmits mechanical energy to a shaft connected
to a generator.
Page 2 of 31
4. Electrical Energy: The generator, a device that converts mechanical energy into electrical
energy, utilizes the rotational motion of the shaft to spin a coil of wire within a magnetic field.
This process, based on the principles of electromagnetic induction, generates an electric current.
In essence, the water wheel acts as a intermediary, transforming the potential energy of the
water into mechanical energy, which is then harnessed by the generator to produce electricity.
This principle is fundamental to hydroelectric power generation, where large-scale waterwheels
(turbines) are used to drive massive generators, producing significant amounts of electricity for homes
and industries.
Markscheme
1 mark for the principal PE-KE-Electrical energy
1 mark for PE and KE explanation
1 mark for how ME converts to electrical energy
Q 1.2
Discuss the limitation of this model if used in real life situation.
A2
Teacher's Explanation
Low Power Output: Water wheels, especially small-scale ones, have relatively low power
output compared to modern turbines. This limits their applicability for powering large appliances
or grids.
Dependence on Water Flow: The effectiveness of a water wheel is directly tied to the flow rate
and water pressure. Fluctuations in water availability due to seasons, droughts, or other factors
can significantly impact power generation.
Limited Locations: Suitable sites for installing water wheels are limited to areas with consistent
water flow and sufficient elevation differences. This restricts their widespread use.
Environmental Impact: Building dams or diverting water for a water wheel can disrupt natural
ecosystems, impacting aquatic life and surrounding habitats.
Maintenance and Repair: Water wheels require regular maintenance to ensure optimal
operation and prevent damage from wear and tear, debris, or flooding. Repairs can be costly and
time-consuming.
Inefficiency: Compared to modern turbines, water wheels are generally less efficient in
converting water energy into mechanical energy. This means a larger volume of water is needed
to produce the same amount of power.
Page 3 of 31
Markscheme
2 marks for any of the above points or any other relevant point
Q 1.3
The figure below shows a uniform plank AB of length 2.0m suspended from two
A1
ropes X and Y.
The weight W of the plank is 210N. The force in rope X is P. The force in rope Y is Q
State the moment of W about B.
Teacher's Explanation
(W × 1.0 OR 210 × 1.0 =) 210 N m
Markscheme
1 mark for 210 x 1
1 mark for 210 Nm (with unit)
Q 1.4
State what is meant by the principle of conservation of energy
A1
Teacher's Explanation
Page 4 of 31
In a closed system, energy cannot be created or destroyed
OR energy can only be transferred from one form to another
OR total energy remains constant
Markscheme
1 mark for the correct statement
Give no marks if "in a closed system" is not mentioned
The figure shows a girl throwing a heavy ball
Q 1.5
State the energy changes that take place from when the girl begins to exert a force on
A2
the ball until the ball hits the ground and stops moving
Teacher's Explanation
Kinetic (energy) to potential (energy) OR gravitational (energy) Potential (energy) OR gravitational
(energy) to kinetic (energy) Kinetic (energy) to thermal (energy) OR heat (energy)
Markscheme
Page 5 of 31
2 marks for correct explanation
Q 1.6
The mass of the ball is 4.0kg. The girl exerts a force on the ball for 0.60s. The speed
A4
of the ball increases from 0m/ s to 12m/s before it leaves the girl’s hand.
Calculate:
1. the momentum of the ball on leaving the girl’s hand momentum.
2. the average resultant force exerted on the ball
Teacher's Explanation
1. (momentum =) mv OR 4.0 × 12 = 48 kg m/s or N s
2. (average force =) momentum change / time OR m(v – u) / t OR (mv – mu) / t OR F = ma AND a =
(v – u) / t OR 48 / 0.60 = 80 N
Markscheme
1. 1 mark for 4 x 12
1 mark for 48 kg m/s or Ns
2. 1 mark for use of correct formula and substituting 48/0.60
1 mark for 80 N
Q 1.7
The figure shows liquid in a cylinder.
A3
Page 6 of 31
The depth of the liquid is 10cm and the radius of the cylinder is 3.0cm. The weight of
the liquid in the cylinder is 2.5N.
Calculate the density of the liquid and state the unit.
Teacher's Explanation
mass = 0.25 (kg) OR ρ = m / V
volume = (π × 0.032 × 0.1 = 2.8 × 10-4 (m3))
density = (0.25 / 2.8 × 10-4) = 890 kg / m3
mass = 250 (g) OR ρ = m / V volume = ( π × 32 × 10 =) 280 cm3 density = (250 / 280 =) 0.89 g / cm3
OR
ρ = F / A = h ρg
ρ = F / Ahg
OR
2.5 / π × 0.032 × 0.1 × 10 = 890 kg / m3
Markscheme
1 mark for correct mass
1 mark for correct volume
1 mark for correct density
Q 1.8
The figure shows a device that measures the pressure of a gas supply.
A1
State the name of the device
Page 7 of 31
Q 1.9
The difference h between the two liquid levels is 2.0cm. The density of the liquid is
A2
800kg/m3. Calculate the difference between the pressure of the gas and atmospheric
pressure.
Q 1.10
A similar device with a tube of smaller cross-sectional area is connected to a gas
A2
supply at the same pressure. State and explain any effect on the value of h
Teacher's Explanation
manometer
Markscheme
1 mark for the correct name
Q 1.11
A laser produces a beam of monochromatic light. State what is meant by the term
A1
monochromatic.
Q 1.12
A vibrating source on a ship produces a sound wave that travels through the ocean.
A1
The wave produced is a longitudinal wave. Explain what is meant by the term
longitudinal wave
Teacher's Explanation
Particles / molecules / water / medium vibrate
Vibration is in the direction travel of the wave
Has compressions and rarefactions
Markscheme
Page 8 of 31
1 mark for mentioning the any of the above points
Q 1.13
The frequency of the sound wave is 800Hz.
A2
(i) The speed of sound in air is 330m/ s. State a typical value for the speed of sound in
a liquid.
(ii)Using your value from (i), calculate the wavelength of the sound wave in the ocean
Teacher's Explanation
(i) Value in range from 900 m / s to 2000 m / s
(ii) v = fλ in any form OR ( λ =) v / f OR answer to (b)(i) / 800
correct evaluation with unit (m)
Markscheme
(i) 1 mark for correct value
(ii) 1 mark for correct substitution
Page 9 of 31
Criteria B and C
Investigation skills
This task (questions 2.1-2.14) addresses the key concept of systems and focuses on criterion
B (Inquiring and designing) and criterion C (Processing and evaluating). In this task you will
investigate different relationships in science.
Ohm’s law describes the relationship between current, voltage and resistance.
A student investigates an electrical circuit containing variable power supply, an ammeter and
a filament lamp (bulb) in which the current through the light can be changed. One of the
circuit diagrams below is incorrect and the other one is correct.
Q 2.1
Explain why the current in the bulb could not be measured using the incorrect
A2
circuit.
Page 10 of 31
Teacher's Explanation
in the incorrect diagram the ammeter is not in series with the bulb the ammeter is not measuring
the current through the bulb or ammeters have a negligible resistance (so in the incorrect
diagram) all/most of the current would flow through it and not through the lamp
Markscheme
1 mark for mentioning incorrect attachment of ammeter
1 mark for mentioning why would the circuit be incorrect
Q 2.2
The student connects the components as shown.
B1
State the independent and the dependent variables in this investigation.
Teacher's Explanation
(independent variable =) voltage, accept potential difference
(dependent variable=) current, accept temperature
Markscheme
1 mark for IV
Page 11 of 31
1 mark for DV
The student decides to measure the current at each of the following voltages:
Voltage (V)
0.0
2.0
4.0
6.0
8.0
9.2
10.0
11.2
12.0
Q 2.3
When asked about the reason for choosing these values the student says:
B3
"I consider this to be a valid variation of voltage as it provides appropriate
number of measurements within the proposed range of voltage I am covering from
0 V to 12 V"
Evaluate the values of voltage the student has chosen.
Teacher's Explanation
collected data is sufficient as 9 measurements (constitute a sample that allows for analysis)
voltage values cover the range proposed by the experiment (but) are not distributed evenly or
are clustered around some areas and there are gaps in some others
Page 12 of 31
Markscheme
1 mark for collection of sufficient data
1 mark for mentioning voltage values are covered over a range in the experiment
1 mark for mentioning voltages are not distributed evenly and are clustered
The student performs the experiment by connecting the circuit as shown below. The lamp is
connected to a temperature sensor and records a range of temperatures and the brightness of
the bulb along with the voltages and currents.
Q 2.4
C3
The student records the following in the notebook:
Organize the data collected by the student in a table
Teacher's Explanation
correct observations should be mentioned
Page 13 of 31
Markscheme
1 mark for making observation table
2 marks for correct placement
Q 2.5
Plot a graph of the above data and draw a line of best fit
C5
Teacher's Explanation
Markscheme
1. correct plotting (3 marks)
2. Correct marking of line (2 marks)
Q 2.6
Using the graph from above, describe the relationship between voltage and
C2
current in the circuit
Page 14 of 31
Teacher's Explanation
The data demonstrates a linear relationship between voltage and current for values below
8V.
The data shows a non-linear relationship between voltage and current for values above
8V.
The qualitative descriptions of filament temperature and bulb brightness provide a
general understanding of the bulb's behavior.
Extra Explanation of the Data
Voltage (V): Increasing linearly from 1V to 12V.
Current (A): Increases with voltage, maintaining a linear relationship up to 8V. Beyond 8V,
the increase in current becomes less proportional to the increase in voltage, simulating the
non-linear behavior of a filament bulb.
Filament Temperature: Qualitative description reflecting the increasing heat of the
filament.
Bulb Brightness: Qualitative description corresponding to the filament's temperature and
the amount of light emitted.
Markscheme
1 marks for mentioning the data demonstrates a linear relationship between voltage and current
for values below 8V
1 mark for mentioning a non-linear relationship between voltage and current for values above
8V.
Resistance (R) is defined as the ratio of voltage (V) across the material to the current (I)
flowing through the material. The unit of resistance is ohm and the symbol is Ω.
R=
Q 2.7
V
I
Describe how resistance changes in the filament across the range of the
C4
experiment. You should take two points from the graph to calculate values of
resistance to support your answer.
Page 15 of 31
Teacher's Explanation
According to the data table and the graph, the resistance appears to be constant up to 8V and
then increases significantly at higher voltages.
As you can see, the resistance is the same (10.0 Ω) at both 2V and 10V, which falls within the
linear region of the graph. This suggests that the resistance remains relatively constant up to
8V.
However, it's important to note that the relationship between voltage and current becomes nonlinear above 8V. This indicates that the resistance is no longer constant in this range. The
calculated resistance at 12V (not shown in the table above) would be significantly higher than
10.0 Ω, reflecting the increased difficulty for current to flow through the filament at higher
voltages.
Q 2.8
Before starting the experiment, the following hypothesis was proposed.
C3
"In all materials, the current was directly proportional to the voltage"
Discuss whether or not the results of the experiment support the hypothesis.
Teacher's Explanation
for directly proportional relationship the graph of the two factors should be a straight line (Give
credit where reference is made to not all materials have been tested)
Either, as appropriate to the data recorded: the graph is not a straight line so the relationship is
not directly proportional (so) the hypothesis is not supported (do not award marks for this
alone)
or
the graph is a straight line so the relationship is directly proportional (so) the hypothesis is
supported (do not award marks for this alone)
Markscheme
2 mark for mentioning how it is not a direct relation (Give credit where reference is made to not
all materials have been tested)
1 mark for mentioning hypothesis is not supported
Page 16 of 31
A second student carries out a similar experiment using a different light bulb. He realizes that
the lamp begins to glow above a certain temperature.
Q 2.9
All materials radiate energy in the form of electromagnetic waves. The frequency
C1
of the waves increases with temperature.
Explain with the reference to the electromagnetic spectrum, why the filament only
glows above a certain temperature.
Teacher's Explanation
only certain frequencies are visible
or
only certain wavelengths are visible above a certain temperature
the EM waves are in the visible range
Markscheme
1 mark for visibility of only certain frequencies
Page 17 of 31
Q 2.10
Kinetic theory describes how particles in materials are in constant motion.
C5
Interpret the results of the experiment and use kinetic theory to explain the
result.
Teacher's Explanation
current increases with voltage/p.d.
the current doesn’t increase as much as temperature increases/at higher temperature
A higher temperature means that atoms in the filament vibrate faster
or
A higher temperature means that atoms in the filament have greater kinetic energy
flowing charges are slowed down by collisions with the vibrating atoms resulting in a smaller
increase of current
Markscheme
1 mark for mentioning increase in current with voltage
1 mark for mentioning the current doesn’t increase as much as temperature increases/at higher
temperature
1 mark for mentioning a higher temperature means that atoms in the filament vibrate faster
1 mark for mentioning a higher temperature means that atoms in the filament have greater
kinetic energy
1 mark for mentioning slowed down by collisions with the vibrating atoms resulting in a smaller
increase of current
Q 2.11
Outline another experiment that the student could perform to extend this
C2
investigation.
Teacher's Explanation
any reasonable suggestion of an extension [1 max],
for example • different component • different material • greater range of voltage/p.d.
correctly linked justification of the suggestion
Page 18 of 31
The image below shows a simple model of a satellite transmission where 's' is the
ground distance between the two stations and 'h' is the height of the satellite above the
surface of the Earth and the 'P' mark shows the limits of the satellite footprint. Signal
travels at the speed of light from the ground station to the satellite and back. A study
is performed to determine if there is a relation between ground distance 's' and
transmission time 'T'
Q 2.12
Identify the independent, dependent and the control variable of the experiment.
B3
Teacher's Explanation
all correct – two marks
two correct – one mark
transmission time – dependent
height – control
ground distance – independent
Markscheme
Page 19 of 31
1 mark for IV
1 mark for DV
1 mark for CV
Q 2.13
Formulate and justify a hypothesis about the relationship between the variables
B3
of the study.
Teacher's Explanation
statement of hypothesis: links independent and dependent variables
correct relationship between variables: increase in ground distance increases transmission time
justification: as distance travels increases so does the time taken
Markscheme
1 mark for statement of hypothesis
1 mark for relationship between variables
1 mark for justification
Heat transfer is the spontaneous exchange of thermal energy between different systems or
objects.
Imagine you are asked to determining the most effective insulating material for keeping hot
beverages warm in a thermos. In order to accomplish this, you set up a simple experiment
using containers filled with hot water and different insulating materials. Your goal is to
measure and compare the rate at which the water cools down when each insulating material
is used.
Page 20 of 31
Q 2.14
Design a scientific investigation to quantify and compare the speed at which the
B 13
temperature of water decreases when different insulating materials are
employed.
In your plan you should include:
the research question that this investigation will test
a hypothesis that can be tested by this investigation
the independent and the dependent variable
one control variable and why it should be controlled
how you will collect sufficient relevant data
a method detailing your procedure including any measuring equipment
needed
Teacher's Explanation
Research Question: How does the temperature of hot water vary with time by a container made
of different insulating materials?
Hypothesis: The insulating material that exhibits the slowest rate of temperature decrease in
hot water will be the most effective for thermal insulation in a thermos.
Independent Variable: time
Dependent Variable: change in temperature
Control Variable: Initial temperature of hot water. It should be controlled to ensure consistency
across all experiments and eliminate its influence on the rate of temperature decrease.
Data Collection: Sufficient relevant data will be collected by measuring the temperature of the
water at regular time intervals as it cools down. The temperature measurements will be
recorded and used to calculate the rate of temperature decrease for each insulating material.
Method/Procedure:
·
Prepare three identical containers (such as mugs or jars) and label them as A, B, and C.
·
Fill each container with the same amount of hot water at a specific starting temperature
(e.g., 90°C).
·
Wrap container A with foam, container B with fabric, and container C with paper, ensuring
that the materials completely cover the containers and are securely fastened.
·
Start a timer as soon as the insulating materials are applied to the containers.
·
Measure and record the temperature of the water in each container at regular time intervals
(e.g., every 5 minutes) using a thermometer or temperature probe.
·
Continue monitoring and recording the temperature until a predetermined end point is
reached, such as when the water temperature drops to a specific threshold or after a set time
duration.
·
Calculate the rate of temperature decrease for each container by determining the change in
temperature per unit time.
Page 21 of 31
Markscheme
1
Research
question
2
3
4
A statement on
the research
question
hypothesis links
IV and
DV, is testable
Hypothesis
attempt at a
hypothesis
a statement on
testable
hypothesis
and with
an attempted
explanation
referencing
relevant
scientific
knowledge
Variables
data
independent,
independent,
dependent
dependent
variable and one
variable and two
control
control
variable stated
variables are
and
stated and
justified
justified
reference to
at least five
at least five
different
different
different
increments or
readings or
readings and
trials
three trials
three trials
method
complete method
IV or DV implied
attempt at
method,
Method
insufficient detail described, could
fully
and
be followed, will
explained and
not likely to give
produce
could be
relevant
relevant data
replicated
data
Page 22 of 31
Criteria D
Applying science
The global context is orientation in space and time. This task (questions 3.1 to 3.7) addresses
the key concept of relationships and assesses criterion D (Reflecting on the impacts of
science).
Density and Force Disparity in Lower Limb Prostheses
Humans have used their understanding of physical principles to develop a variety of systems
that help people without limbs adapt to their environment.
Prostheses (replacements for a missing body part) are widely used by athletes in
competitions. the design of the prostheses needs to take into account physical differences to
give good performance while keeping the competition fair.
The following image shows three athletes using different types of prostheses:
Page 23 of 31
Source: www.alamy.com
When a force is applied to a material it can cause a change in length of that material. Young's
modulus (E) is a measure of how much a material can be changed. Stiff of more rigid
materials have a bigger value of E as compared to softer materials.
The table below shows some data for bone as well as for some of the materials used in a
prostheses.
Page 24 of 31
Material
E/GPa
Density/ g cm-3
Polypropylene
2
0.95
Bone
15
1.75
Material X
17
4.23
Carbon Fiber
40
1.60
Aluminium
69
2.72
Steel
200
7.85
Q 3.1
State the name of the most rigid material in the table
D1
Teacher's Explanation
Steel
Markscheme
1 mark for steel
Q 3.2
Suggest why the E value of polypropylene means it is not suitable of prostheses
D1
used by the athletes.
Teacher's Explanation
Any relevant point, for example • too soft • less rigid • not able to support high forces during
competition
Page 25 of 31
Markscheme
1 mark for any relevant point as mentioned in the explanation
Scientists have developed Material X which has Young's modulus similar to human bone.
Consider the two identical limbs designed for particular athletes shown in the figure below:
Q 3.3
Use information from the table to discuss how the properties of carbon fiber and
D4
material X could help people without limbs adapt to their environment.
Teacher's Explanation
compares the density of material X to carbon fibre or to bone
suggestion of how this could affect the function of the prosthesis
compares the E or stiffness or Young’s modulus of material X to carbon fibre or to bone
suggestion of how this could affect the function of the prosthesis
Page 26 of 31
A concluding comment, for example • a leg is more complicated than the bone alone • muscles
are also important • a recommendation suggesting which of the two materials would be better
for performance in sport
Markscheme
1 mark for comparison of the 2 materials
1 mark for suggestion of the prosthesis
1 mark for comparison of E
1 mark for concluding appraisal
Some competitions involve regular and prosthesis-aided athletes.
Q 3.4
Discuss and evaluate the implications of this type of technological advance in
D 11
relation to the fairness of the competition and inclusive access of to sport for all
athletes. In your answer you should consider:
the ethical implication of improving performance with prostheses
Page 27 of 31
the social implications of including prostheses-aided athletes in
competitions
a concluding appraisal
Teacher's Explanation
Markscheme
Marking scheme as per the explanation above
Landmines around the world are responsible for thousands injured people and animals. As
advanced prosthetic limbs are not available on low incomes, solutions have been found for
reducing costs to help the amputees. Recycled aluminium was used to give an elephant that
stepped onto a landmine the possibility of walking again. Human understanding of scientific
principles was used to create an artificial leg.
Page 28 of 31
Q 3.5
Calculate the pressure on the ground when an elephant weighing 30,000 N is
D1
standing on only three feet. Assume each foot has an area of 0.2 m2
Teacher's Explanation
50 000
Nm-2 or N/m2 or Pa or pascal(s)
Markscheme
1 mark for the correct answer as above
Q 3.6
Explain how the design of the prostheses takes account of pressure when:
D3
1. Creating contact with the ground
Page 29 of 31
2. Providing comfort to the elephant when connecting the prosthesis to its
upper leg
Teacher's Explanation
pressure is inversely proportional to area
Contact with the ground contact area between the prosthesis and the ground is as large as that
of a natural foot
pressure on the ground allows the elephant to walk without the artificial foot sinking into the
ground
Contact with the limb:
area of contact between the prosthesis and the elephant’s skin is maximized the elephant’s skin
feels less pressure making the limb comfortable
Markscheme
1 mark for mentioning how pressure and area are inversely proportional
1 mark for mentioning relation between contact between surface area of prosthesis and ground
1 mark for mentioning how the contact between the pressure of prosthesis and limb
Q 3.7
Outline the advantages and disadvantages a prosthetic limb would have on an
D4
elephant when returned to its natural habitat. Evaluate whether or not you think
elephants with prosthetic limbs should be returned to their natural habitat.
Teacher's Explanation
Any advantage,
for example • Allows movement Justification of advantage, for example • Able to find food over
a wider area
Any disadvantage, for example • Never as good as original limb
Justification of disadvantage,
for example • Prosthetic limb/attachment might need maintenance, this would not be possible in
its natural habitat
Any additional advantage or disadvantage and justification,
for example • Male elephants fight and the prosthetic limb would not be sturdy enough
A simple evaluative statement
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The evaluative statement is justified
Markscheme
1 mark for advantage,
1 mark for justification of advantage
1 mark for disadvantage
1 mark for justification for disadvantage
Page 31 of 31