25 Unique Physics IA Ideas: Internal Assessment Topics
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What is an internal assessment?
The Internal Assessment is a project that every student must complete in all IB classes. This project is mostly completed on your own, therefore it’s an amazing opportunity to put the theoretical physics learned during classes into practice. Your course teacher (or your tutor) will help you in the creation of a physics exploration. As you have to come up with the topic, experiment and execute it on your own, you might find it challenging or even intimidating to come up with just the right idea. Look no further, we have therefore created a list with unique ideas that could inspire your physics IA!
Characteristics of a good IA
The goal of the internal assessment is to show your ability to use the knowledge acquired during classes in practice. It does not need to be innovative or groundbreaking, so you don’t have to worry about needing to come up with complicated equations and methodology. You are asked to create a research question, which by using appropriate physics formulas, experimental methods, measurements and calculations can be answered. You don’t have to limit yourself to just one area of physics. Creating an exploration that ties together areas such as mechanics and thermodynamics will make it more interesting, as well as help you see just how closely related all fields are to each other.
As you will spend many days working on the IA, you should choose a subject that personally interests you. An exploration written on an easier topic but showing clear understanding and passion will always be perceived better than a complicated one, which does not resonate with you in any way.
25 original Physics IA ideas
Buoyancy and density
During classes, you have encountered questions where a body is submerged in a liquid, then tested what fraction of it is not in the liquid. Your experiment could focus on taking objects (or liquids) of different densities and testing how that affects the buoyancy force present in the system.
Changing spring constant
Every spring has a unique spring constant assigned, which can be found through Hooke’s law. However, is it always the same number under all external conditions? You can test this by heating and cooling down a spring, and then measuring whether it has any effect on its extension and spring constant.
Friction and energy loss
When solving physics questions, you are often asked to assume no air friction or no surface friction. You can create an experiment with an object going down slopes of different friction coefficients and test whether the friction contribution to the overall motion is truly negligible.
Terminal velocity
In sports, there are a variety of differently shaped balls, which affect their aerodynamics and the time taken to reach terminal velocity. To what extent is it related to the shape of the ball and its cross-sectional area? You can focus on finding the best area-to-terminal velocity ratio and discuss the factors potentially affecting it.
The gas constant
In the ideal gas law, we take R = 8.31J mol-1K-1, but where exactly does this number come from? You can create an experiment testing the relationship between the volume and pressure of a certain amount of gas. The graph of the inverse of volume against pressure should be a straight line, where the gradient is expected to be the gas constant.
Viscosity
From Stoke’s law, we know how the viscosity of a fluid affects the drag force experienced by a body submerged in it, assuming that the value of viscosity is constant. Is that always true? You can create an experiment to see whether the temperature of a fluid affects its viscosity, thus resulting in a changing drag force experienced by a body.
Specific heat capacity
Every liquid has its specific heat capacity and in many physics questions, these values are given as constants. Your IA could explore how adding salt into water, thus changing its density may affect the specific heat capacity of the liquid. As the concentration of salt increases, an increase in the boiling point of the solution and a decrease in the specific heat capacity are expected.
Speed of sound
We assume that the speed of sound is constant and approximately 340 ms-1 in air, however, this number is dependent on what medium the sound is travelling through. Your experiment can test the relationship between the speed of sound passing through a water-sugar solution and its density (each time changing the ratio between water and sugar to increase its density).
Pendulums at large angles
In class, you might have seen that pendulums follow simple harmonic motion, yet the examples only showed what happens at small angles of displacement. What happens at greater angles? Does the system still follow SHM? You can create a pendulum system and test whether the angle affects the accuracy with which the SHM model predicts its subsequent movement.
Heating circuits
When working with circuits, the ideal conditions are always set at room temperature and no direct sunlight affects it. This is done to ensure the components do not overheat. Your experiment can explore how other variables are affected when the temperature of a resistor is varied, to see just how crucial the ideal conditions are for the circuit to operate correctly.
Torricelli’s law
This theorem states that the velocity with which a liquid is leaving a container is directly proportional to the square root of the vertical distance between the surface of the liquid and its centre. You can create an experiment where you take a bottle, make holes at different heights and test whether the aforementioned relationship holds true.
Vaporization
While studying with a mug of coffee or tea next to you, you might have seen that the time taken to cool down differs depending on the size and material of the cup. Your IA can focus on the exploration of how the surface area of the drink may affect the rate of its vaporization. Watch out for the materials used, and take into account whether it is a good insulator or conductor.
Intensity
In class when discussing waves and optics, the teacher must have mentioned and explained the inverse square law. You could explore the relationship between the intensity of emitted light and the distance away from the light source. If light intensity seems too difficult to measure, you can do exactly the same experience but using sound waves.
Refractive index
Snell’s law, also known as the law of refraction, is the basis for understanding the relationship between the incident angles, phase velocities and refractive indices. This law can be tested by using sucrose in water, changing its amount in the mixture and seeing whether the angle of refraction of the light passing through it changes. If it does, following Snell’s law, so will the refractive index.
Refraction and temperature
Building upon the previous idea, you can expand the IA by seeing whether the temperature of the liquid affects its refractive index. The working principles and theory for both are exactly the same, you can again make use of a mixture of water and sugar. Use a fixed amount and measure the refraction angles for different temperatures of the liquid.
Siphons
This is a tube that allows for the transfer of liquids from a reservoir at a higher elevation to another at a lower elevation, although a great portion of this motion occurs with the liquid moving upwards with no pump required. Your IA could investigate how its cross-sectional area may influence the flow rate of the liquid when moving from one container to another.
Ohm’s law
In many physics questions, you are to assume that components of a circuit, such as resistors or light bulbs, are following Ohm’s law. It states that there is a linear relationship between the voltage and current flowing through a component. However, this is only an approximation for small values of I and V. You can create an experiment in which you will test for what values this law no longer holds true.
Ideal circuit components
Similarly to the above, the concept of ideal ammeters and voltmeters does not exist in reality. Nonetheless, we still use it in almost every single circuit. Your experiment can focus on measuring what is the true resistance of an ideal voltmeter or ammeter. The first one should be tending to infinity, whereas the second one should be close to zero.
Transformers
This is a component which allows for the transfer of electrical energy from one circuit to another. In realistic conditions, its efficiency is always less than one and it is easily affected by temperature. As both of these concepts deal with energy gain and loss, your IA could focus on the relationship between the efficiency and temperature of a transformer.
Internal resistance
As every electrical component has some internal resistance, this may affect the voltage required for an element to work as expected. Your experiment could take every component from a circuit, measure the internal resistance of each and discuss how these values may affect the overall working of the electrical system.
Moment of inertia
Many three-dimensional shapes experience different moments of inertia. As it is directly proportional to the angular momentum, it affects the frequency of its rotations. Your IA can take a few shapes (such as empty and solid cylinders, solid spheres and a spherical shell), roll each of them down the same incline and through the use of inertia conclude which shape can reach its bottom the fastest.
The twin paradox
Thanks to Einstein’s work on the theory of special relativity, we know that time and space are relative to the frame of reference used. A great example showing its main principles is the twin paradox, which explores the theoretical case of two twins - one goes into space and comes back younger than the one who stayed on Earth. A real treat for fans of relativity, philosophy and theoretical physics!
Doppler effect
The most common example demonstrating the Doppler effect is an ambulance passing next to your window, and the sound frequency appears as the greatest when the closest to you. You can create an experiment where you will explore how the radius of an oscillating sound source may affect the perceived frequencies of a stationary observer.
Wind turbines
It is predicted that around 8% of all energy in the world in 2023 was produced through wind turbines, thus making it an important source of clean and renewable energy. Their efficiency is strongly connected to the shape of their blades, the angle at which they are placed with respect to each other, as well as wind speed. Your IA can explore relationships between these variables.
Fundamental frequency
If the topics of standing and transverse waves sparked your interest in classes, this topic can help you see them in practice. An example experiment could take a look at how the length, tension and mass of a string may affect the fundamental frequency of a standing wave.
Still unsure?
We understand that it is not easy to choose a subject that you’d like to pursue for your experiment. Do not worry, our tutors are ready to help! We can help you with finding a suitable research question, general structuring and resolving any additional issues you may encounter while writing your IA. Simply sign up here for the Think Smart Tutoring services to set up your introductory lesson and connect you with the best suitable tutor for your needs.
