You must have some basic MCAT physics knowledge to do well on your test. While physics does not have a dominant presence in the exam, knowing and understanding physics equations, concepts, and laws are important for future physicians. In this ultimate prep guide, I will outline how much physics is actually on the MCAT, what concepts and equations you should expect on your test day, how to determine which physics concepts you need to review, and how you can get yourself ready to answer any MCAT physics problem you encounter.
Here’s What We’ll Cover:
Questions concerning physics are only found in the first section of the MCAT: The Chemical and Physical Foundations of Biological Systems. This section of the MCAT consists of 59 questions with only 25% of questions related to introductory physics: some of the questions are passage-based and some are discrete. You will have 95 minutes to complete this section of the exam. You will not be provided with a calculator, but you will be supplied with a periodic table. The physics content that is featured in the MCAT is covered in introductory courses by all major colleges and universities in the United States and Canada. When you start your MCAT prep, if you find that there are some unfamiliar physics topics and subtopics, it is your responsibility to learn them on your own time. Remember, many medical schools in Canada and the US do not have strict medical school prerequisites – some don't even demand any scientific knowledge from their applicants. However, to successfully prepare for the study of medicine and your MCAT exam, you must have some basic scientific knowledge. The MCAT does not demand you to be a physics expert. Most of the topics you will encounter in MCAT practice and the AAMC guidelines are covered in introductory physics classes, but please do not panic if during your MCAT prep you encounter some concepts you’re unfamiliar with.
Do you want us to help you prepare for your MCAT exam?
Your physics knowledge will be tested in two subsections of the Chemical and Physical Foundations of Biological Systems section of the MCAT. Most of the physics content will be covered in the Foundational Concept 4 subsection, with some physics present in the Foundational Concept 5 subsection.
Foundational Concept 4
Human bodies are complex living organisms that transport materials, sense their environment, process signals, and respond to changes using processes that follow the laws of physics. They can be analyzed and understood by using equations that model behavior at a fundamental level. Basic physics equations and concepts inform your knowledge of the physiological functions of the human body, including respiratory, cardiovascular, and neurological systems. As a future physician you must be familiar with the following Foundational Concept 4 themes and their related concepts:
Category 4A focuses on motion and its causes, and various forms of energy and their interconversions.
- Units and dimension
- Vectors, components
- Vector addition
- Speed, velocity (average and instantaneous)
- Newton’s Frist Law, inertia
- Newton’s Second Law (F=ma)
- Newton’s Third Law, forces equal and opposite
- Friction, static and kinetic
- Center of mass
- Vector analysis of forces acting on a point object
- Torques, lever arms
- Work done by a constant force: W=Fd cosϴ
- Mechanical advantage
- Work Kinetic Energy Theorem
- Conservative forces
Energy of Point Object Systems
- Kinetic Energy: KE = ½ mv2 ; units
- Potential Energy: PE = mgh (gravitational, local); PE = ½ kx2 (spring)
- Conservation of energy
- Power, units
- Amplitude, frequency, phase
- Transverse and longitudinal waves: wavelength and propagation speed
Category 4B focuses on the behavior of fluids, which is relevant to the functioning of the pulmonary and circulatory systems.
- Density, specific gravity
- Buoyancy, Archimedes’ principle
- Hydrostatic pressure: Pascal’s Law and Hydrostatic pressure P=pgh (pressure vs. depth)
- Viscosity: Poiseuille Flow
- Continuity equation (A∙v = constant)
- Concept of turbulence at high velocities
- Surface tension
- Bernoulli’s equation
- Venturi effect, pitot tube
- Absolute temperature, (K) Kelvin Scale
- Pressure, simple mercury barometer
- Molar volume at 0°C and 1 atm = 22.4 L/mol
- Ideal gas: definition, Ideal Gas Law PV=nRT, Boyle’s Law PV=constant, Charles’ Law V/T=constant, Avogadro’s Law V/n-=constant
- Kinetic Molecular Theory of Gases: heat capacity at constant volume and at constant pressure and Boltzmann’s Constant
- Deviation of real gas behavior from Ideal Gas Law: qualitative and quantitative (Van der Waal’s Equation)
- Partial pressure, mole fraction
- Dalton’s Law relating partial pressure to composition
Category 4C highlights the nature of electrical currents and voltages; how energy can be converted into electrical forms that can be used to perform chemical transformations or work; and how electrical impulses can be transmitted over long distances in the nervous system.
- Charge, conductors, charge conservation
- Coulomb’s Law
- Electric field E: field lines and field due to charge distribution
- Electrostatic energy, electric potential at a point in space
- Current I = ΔQ/Δt, sign conventions, units
- Electromotive force, voltage
- Resistance: Ohm’s Law I=V/R, Resistors in series, Resistors in parallel, Resistivity ρ = R•A / L
- Capacitance: parallel plate capacitor, energy of charged capacitor, capacitors in series, capacitors in parallel, dielectrics
- Conductivity: metallic and electrolytic
- Definition of magnetic field B
- Motion of charged particles in magnetic fields; Lorentz force
Category 4D emphasizes the properties of lights and sound; how the interactions of light and sound with matter can be used by an organism to sense its environment; and how these interactions can also be used to generate structural information or images.
- Production of sound
- Relative speed of sound in solids, liquids, and gases
- Intensity of sound, decibel units, log scale
- Attenuation (Damping)
- Doppler Effect: moving sound source or observer, reflection of sound from a moving object
- Resonance in pipes and strings
- Shock waves
Light, Electromagnetic Radiation
- Concept of Interference; Young Double-slit Experiment
- Thin films, diffraction grating, single-slit diffraction
- Other diffraction phenomena, X-ray diffraction
- Polarization of light: linear and circular
- Properties of electromagnetic radiation: velocity equals constant c, in vacuo
- Electromagnetic radiation consists of perpendicularly oscillating electric and magnetic fields; direction of propagation is perpendicular to both
- Classification of electromagnetic spectrum, photon energy E=hf
- Visual spectrum, color
- Reflection from plane surface: angle of incidence equals angle of reflection
- Reflection, refractive index n; Snell’s law: n1 sin θ1 = n2 sin θ2
- Dispersion, change of index of refraction with wavelength
- Conditions for total internal reflection
- Spherical mirrors: center of curvature, focal length, and real virtual images
- Thin lenses: converging and diverging lenses, use of formula 1/p + 1/q = 1/f, with sign conventions, and lens strength, diopters
- Combination of lenses
- Lens aberration
- Optical Instruments, including the human eye
Category 4E focuses on subatomic particles, the atomic nucleus, nuclear radiation, the structure of the atom, and how the configuration of any particular atom can be used to predict its physical and chemical properties.
- Atomic number, atomic weight
- Neutrons, protons, isotopes
- Nuclear forces, binding energy
- Radioactive decay: α, β, γ decay and half-life, exponential decay, semi-log plots
- Mass spectrometer
- Mass spectroscopy
- Orbital structure of hydrogen atom, principal quantum number n, number of electrons per orbital
- Ground state, excited states
- Absorption and emission line spectra
- Use of Pauli Exclusion Principle
- Paramagnetism and diamagnetism
- Conventional notation for electronic structure
- Bohr atom
- Heisenberg Uncertainty Principle
- Effective nuclear charge
- Photoelectric effect
Foundational Concept 5
This subsection of the MCAT contains only one physics content area, but keep in mind that all of these concepts are related, whether they are organic chemistry, biochemistry, or physics. Foundational Concept 5 subsection covers the following content and related physics concepts:
Category 5A emphasizes the nature of solution formation, factors that affect solubility, and the properties and behavior of aqueous solutions, with special emphasis on the acid-base behavior of dissolved solutes.
Category 5B focuses on molecular structure and how it affects the strength of intermolecular interactions.
Category 5C emphasizes how differential intermolecular interactions can be used to effect chemical separations.
Category 5D emphasizes the varied nature of biologically-relevant molecules, and how patterns of covalent bonding can be used to predict the chemical reactivity of these molecules and their structure and function within a living system.
Category 5E emphasizes how relative energy dictates the overall favourability of chemical processes and the rate at which these processes can occur.
Energy Changes in Chemical Reactions - Thermochemistry, Thermodynamics
- Thermodynamic system – state function
- Zeroth Law – concept of temperature
- First Law − conservation of energy in thermodynamic processes
- PV diagram: work done = area under or enclosed by curve
- Second Law – concept of entropy: entropy as a measure of “disorder” and relative entropy for gas, liquid, and crystal states
- Measurement of heat changes (calorimetry), heat capacity, specific heat
- Heat transfer – conduction, convection, radiation
- Endothermic/exothermic reactions: enthalpy, H, and standard heats of reaction and formation and Hess’ Law of Heat Summation
- Bond dissociation energy as related to heats of formation
- Free energy: G
- Spontaneous reactions and ΔG°
- Coefficient of expansion
- Heat of fusion, heat of vaporization
- Phase diagram: pressure and temperature
Learn what is a good MCAT score in our video:
It can be difficult figuring out when to start studying for the MCAT. Not knowing when and where to start your MCAT prep can be overwhelming. Your first step should be figuring out your baseline. To do this, we highly recommend that you take an MCAT diagnostic test. A practice exam will help you determine which disciplines and concepts you need to improve on, including the physics content you should review. Tip: the AAMC practice tests are the most realistic when it comes to determining which content to expect on the real exam. Some practice tests, like Kaplan, are much more difficult and cover physics content that you would never expect on the real MCAT test. If you would like to get an idea of the level of difficulty you can expect on the test day, make sure to take several AAMC diagnostic tests.
When you take the initial practice test, do not try to ace it. Simply pay attention to the content areas, disciplines, concepts, and equations that are challenging for you. Once you review your practice test results, you can start creating your MCAT study schedule. Give yourself an ample amount of time to prepare for this challenging exam. We highly recommend that you set aside no less than six months to study, review, and practice for the MCAT. Remember, in addition to reviewing physics, you will also need to go over some MCAT biology questions, MCAT chemistry questions, MCAT psychology content, and devise a foolproof MCAT CARS strategy. This is why having a thorough MCAT prep schedule is key – you need to outline what content to cover and the study strategies you will implement. If your knowledge of physics is lacking, be sure to include the MCAT physics content you need to review and definitive tactics you will use to tackle it.
1. Remember, it’s not as scary as it looks
Most physics passages look intimidating in practice tests, but the questions typically simply require equation manipulations or application of very basic principles. Prioritize reviewing equations and concepts that are outlined in the AAMC’s official content list, don’t get bogged down by complicated material that has almost no chance of appearing on the test. Do not overlook big and important concepts that are more likely to be included in the MCAT.
2. Know your units
You must know how to convert between units without a calculator. Keep this in mind when you are preparing and writing your MCAT. Get comfortable performing quick unit conversions because sometimes that’s all you need to do to find the correct answer among the MCAT answer options. Practice messing with one of the variables to see what happens to the rest of the equations.
Try re-arranging equations to solve for a particular variable. Being comfortable with playing with different physics equations may help you avoid errors – if you can easily isolate individual variables and solve the equation every time, it demonstrates your thorough understanding of the equation.
3. Flashcards and memorization
Many students use flashcards as a memorization technique. While writing down formulas, concepts, and ideas on flashcards may be a great way to start your MCAT prep, they cannot be the only prep technique you use. Remember, one of the challenges of the MCAT is that you will be faced with physics problems to which you will need to apply the equations. Rather than simply memorizing them, you must understand these equations to be able to use them on any problem you encounter. If you are using flashcards, be sure to also incorporate a lot of practice with sample physics questions and MCAT diagnostic tests.
4. Practice, practice, practice
Understanding physics equations and concepts takes practice. If you are really worried about your physics knowledge, work to build your understanding through practice and internalize the concepts you cover. You can use different practice tests and platforms like UWorld, Examkrackers, Khan Academy, and more. Remember, some practice tests and materials are often more difficult than the actual MCAT exam. Some of these prep materials cover equations and problems that are not included in the exam at all. Keep in mind the MCAT looks to establish if you understand broader concepts outlined in the AAMC content list, so don’t get bogged down by the nitty-gritty details of complex physics concepts and equations.
5. Explain physics concepts to others
Using active study strategies will help you internalize physics concepts. In addition to reading and making notes, you should explain what you learn to others. If you can describe a physical process to a friend or a colleague, you are on the right track in your MCAT prep. Explaining concepts to others can also reveal your weaknesses and parts of the concepts you need to focus on. Pay attention if any content gaps pop up while you are playing the role of an instructor.
6. Get a tutor for MCAT physics
You do not need to have scholarly knowledge of physics to get a great MCAT score. While you are strongly encouraged to take some introductory physics classes during your undergraduate, some students forego them. If you're struggling with your physics prep, it might be wise to get an MCAT tutor who can help you go over the necessary MCAT physics equations. Again, you do not need to hire a tutor for comprehensive MCAT prep, especially if you feel comfortable with the other MCAT sections. But if you struggle with physics, scheduling a couple of sessions with an expert might be useful.
The heme enzyme indoleamine 2,3 dioxygenase (IDO) catalyzes Reaction 1, the first and rate-determining step of L-tryptophan (Compound 1) metabolism, and is an important enzyme of the human immune system.
The IDO-catalyzed oxidation of Compound 1 by H2O2 does not occur. However, researchers have recently discovered that IDO-catalyzed oxidation of indole (Compound 3) by H2O2 (Reaction 2) does occur.
Under the conditions employed, the number of catalytic turnovers appeared to stop at roughly 100, on average. A plot of the concentration of Compound 3 that was oxidized versus the concentration of H2O2 employed, at two different initial concentrations of IDO, gave the results shown in Figure 1.
Aerobic oxidation of Compound 3 in the presence of 18O-labeled H218O2 resulted in the formation of 18O-labeled oxidation products (Table 1).
The formation of Compound 6 does not appear to be the result of a sequential oxidation process. Isotopically labeled Compound 4 does not exchange 18O for 16O in water over 3 hours, but Compound 6 completely loses its 18O label in unlabeled water over the same time period.
Adapted from: Kuo HH, Mauk AG. Indole peroxygenase activity of indoleamine 2,3-dioxygenase. Proceedings of the National Academy of Sciences of the United States of America. 2012;109(35):13966–71.
1. The progress of Reaction 2 can be monitored by observing what change to the IR spectrum of the product mixture?
A) Appearance of a broad peak at 3400 cm–1
B) Disappearance of a broad peak at 3400 cm–1
C) Appearance of a sharp peak at 1700–1750 cm–1
D) Disappearance of a sharp peak at 1700–1750 cm–1
Correct Answer is C) Appearance of a sharp peak at 1700–1750 cm–1
Rationale: This question requires the test taker to combine knowledge about infrared spectroscopy with reasoning about the structural differences between the products and reactants of Reaction 2. The test taker must work with the scientific model of the differences in IR absorbance of various functional groups and apply this model to the experiment described in the passage. Recognition of the presence of additional carbonyl groups in the products of the reaction should lead the test taker to conclude that appearance of a peak between 1700–1750 cm–1 in the IR spectrum would provide the most effective way to monitor product formation.
2. The following kinetic parameters were obtained for the IDO-catalyzed oxidation of Compound 3 by H2O2 in the presence of L-Trp.
Based on this data, what effect does L-Trp have on the reaction?
A) L-Trp oxidizes Compound 3 directly.
B) L-Trp is oxidized instead of Compound 3.
C) L-Trp does not interact with the enzyme.
D) L-Trp inhibits the enzyme.
The correct Answer is D) L-Trp inhibits the enzyme.
Rationale: This question requires the test taker to combine knowledge of enzyme kinetics with interpretation of data. The test taker must understand what the decreasing values of kcat in the presence of higher concentrations of L-Trp mean with respect to the kinetics of IDO-catalyzed indole oxidation. The kcat is representative of the rate of product turnover, which means that the enzyme produces less product in the presence of L-Trp. Combining this trend in the data with a knowledge of enzyme kinetics, it can be concluded that L-Trp is inhibiting the reaction.
3. Which experiment can be used to show that Compound 6 is not formed sequentially from either Compound 4 or Compound 5?
A) Conduct the reaction of Compound 4 with Compound 5, and identify the products.
B) Oxidize Compound 4 and Compound 5 with IDO/H2O2, and identify the products.
C) Reduce pure Compound 6 without added catalyst, and identify the products.
D) Conduct the reaction of Compound 2 with H2O2 without added catalyst, and identify the products.
The correct Answer is B) Oxidize Compound 4 and Compound 5 with IDO/H2O2, and identify the products.
Rationale: This question requires the test taker to apply knowledge about how enzymes catalyze reactions to the design of an experiment. The question asks how researchers can be sure that Compound 6 is not formed from either Compound 4 or Compound 5 in a sequential enzyme mechanism. Enzymes are not used up during catalysis, so any experiment that includes just Compound 4 or just Compound 5 would determine if either is also a substrate for IDO-catalyzed conversion to Compound 6. Having both compounds in solution with IDO adds unnecessary complexity to the interpretation of the experimental results. Examining the products of IDO-catalyzed reduction of Compound 6 would not give the necessary direct evidence, as Compound 6 could be sequentially reduced to Compound 3.
1. How much physics is on the MCAT?
According to the AAMC guidelines, only 25% of the first section of the MCAT tests your knowledge of physics. For a detailed breakdown of each MCAT section, be sure to check out our blog “How Long is the MCAT?”
2. How long is the Chemical and Physical Foundations of Biological Systems section of the MCAT?
This section is the first of the four MCAT sections. You will encounter 59 questions and have 95 minutes to complete them. Out of these 59 questions, 44 are passage-based. You will be presented with ten passages about chemistry and physics topics and you will be asked four to seven passage-based questions after each passage. There will also be 15 stand-alone discrete questions dispersed in between passages.
3. How can the MCAT diagnostic test help me determine which physics concepts I should cover?
Taking the initial practice test demonstrates your baseline. As you are going through the questions, pay attention to how well you are doing in questions related to physics. When you review your practice test result, notice how well you did in the first section of the practice test. Be sure to include physics equations and concepts you need to review in your study schedule.
4. Are there any strategies I can use to memorize the physics equations and concepts?
Some students are used to creating flashcards to study for their tests, but memorizing equations for the MCAT may not be the best study strategy. Here are some tactics you can try using to internalize the physics content you review:
- Write down the equation you are trying to understand several times in your notebook. See if you can write down the equation without referencing your study notes.
- Try writing down what the equation means using sentences. Communicating what the equations mean in words indicates that you understand what kind of physical processes the equation stands for.
- Apply the equation to several practice problems.
- Try grouping several equations together by topic to see similarities between equations that you are struggling with and ones that you have already mastered.
- Research if you can find any mnemonic tactics to remember the physics equations you will need for the MCAT.
Remember, memorizing an equation is futile if you do not understand it. You cannot truly use an equation to solve a problem if you do not truly comprehend it. If you are finding that certain equations are particularly challenging, review each part of the equation and work to understand how and why they work together. You should also review your notes and equations that deal with foundational concepts that you learned previously. It is possible that knowledge gaps in previously covered physics concepts are hindering your understanding of other physics equations.
5. If I did not take the prerequisite, how should I prepare?
Even if you have not taken a prerequisite course, you can prepare for the physics portion of the MCAT if you have enough time. Try to get an introductory physics textbook and give yourself several months to read through all the concepts. Do not forget to follow the steps we outlined above, such as practicing and trying active forms of learning. Reach out for help and get a tutor if needed. If you give yourself enough time, you can prepare for this challenging section.
6. How important is the physics section compared to the rest of the MCAT?
The chemistry and physics section is as important as the other sections. Some schools may weigh some sections more than others, but overall, a well-balanced score with relative parity from section to section shows admissions committees that you are equally strong at all the concepts tested on the MCAT.
No one can deny that the MCAT is a challenging test. Not only is it a very long test, but it also covers a wide variety of topics and disciplines, from physics to organic chemistry, to sociology, and even the liberal arts if you look at some of the MCAT CARS passages. Your study tactic must also include a variety of revision tools. However, with the right prep strategy and a good study schedule, you can prepare yourself for success.
Only take the test when you are ready. While you are taking the diagnostic tests, pay attention to your practice score and improvement. Take as many practice tests as you need and make sure that you are consistently scoring in the 90th percentile before you schedule your exam on one of the MCAT test dates.
9. I really want to go to medical school, but is there any way to avoid the MCAT?
Yes, you can get into some medical schools without writing the MCAT. For example, some medical schools in Quebec and medical schools in Ontario do not ask their applicants for MCAT scores, such as the University of Ottawa medical school and Northern Ontario School of Medicine. For a full list of medical schools that do not require the MCAT, visit our blog.
10. How important is my MCAT score?
Medical school acceptance rates in the US and Canada demonstrate that your GPA and MCAT scores are the first hurdle you have to overcome during the application review process. Many medical school admissions committees weed out applicants with lower GPA and MCAT scores in the first stages of the review without even taking a look at their medical school personal statement or the AMCAS Work and Activities section. If you want to have a good chance of getting accepted into a school of your choice, make sure that your MCAT score at least matches the average MCAT score of the previously admitted cohort.
Do you want us to help you prepare for your MCAT exam?
To your success,
Your friends at BeMo
BeMo Academic Consulting
Source: AAMC Sample Question Guide