Physics for the MCAT Exam

Common failure modes

These are the patterns that cause most candidates to lose marks on this topic. Recognising them in advance is half the work.

• !Not recognising when to use kinematics vs. energy conservation — both may solve a problem, but one is much faster
• !Confusing series and parallel resistance/capacitance rules — they invert between the two configurations
• !Misapplying the lens equation (1/f = 1/do + 1/di) — especially sign conventions for concave vs. convex lenses
• !Forgetting that MCAT fluid mechanics uses Bernoulli and Poiseuille — both appear in cardiovascular physiology passages

Study tips

• 1Memorize the six key physics equations that AAMC lists as foundational: F = ma, W = Fd, P = W/t, PV = nRT, Q = mcΔT, and the wave equation v = fλ.
• 2Practice Bernoulli's equation using blood-flow examples. Venturi effect (narrowed vessels = faster flow, lower pressure) is a common MCAT passage theme.
• 3Drill the thin-lens equation with sign conventions: real images have positive image distance; virtual images negative. For the eye, hyperopia needs converging lens, myopia diverging.
• 4Review the Doppler effect conceptually — the MCAT tests direction (source approaching = higher frequency) more than calculation.

Sample MCAT Physics questions

These sample items mirror the format and difficulty of real MCAT questions. Practice with thousands more on the free Koydo question bank.

1. 1

   A ball is dropped from rest at a height of 80 m. Ignoring air resistance, what is the ball's speed just before it hits the ground? (g = 10 m/s²)

   • A20 m/s
   • B40 m/sCorrect
   • C80 m/s
   • D160 m/s
   Why this answer?

   Using energy conservation: mgh = ½mv². Simplify: v = √(2gh) = √(2 × 10 × 80) = √1600 = 40 m/s. This is faster than using kinematics equations and reflects the MCAT preference for energy methods. (Illustrative.)

2. 2

   A patient has a blood vessel with radius r. Atherosclerosis reduces the radius to r/2. By what factor does resistance to blood flow change? (Poiseuille's Law: R ∝ 1/r⁴)

   • A2-fold increase
   • B4-fold increase
   • C8-fold increase
   • D16-fold increaseCorrect
   Why this answer?

   Poiseuille's Law: resistance R = 8ηL/(πr⁴). If r decreases by factor of 2, resistance increases by 2⁴ = 16-fold. This is why even modest arterial narrowing dramatically increases cardiac work — a high-yield MCAT physiology-physics bridge concept.

3. 3

   An object is placed 30 cm from a converging lens with focal length 10 cm. The image is:

   • AVirtual, erect, and magnified
   • BReal, inverted, and located 15 cm beyond the lensCorrect
   • CReal, inverted, and located at infinity
   • DVirtual, inverted, and diminished
   Why this answer?

   1/f = 1/do + 1/di → 1/10 = 1/30 + 1/di → 1/di = 1/10 − 1/30 = 3/30 − 1/30 = 2/30 → di = 15 cm. Positive di means the image is real and on the opposite side of the lens. Real images from converging lenses are always inverted.