Harvard PHYSICS 15A: Introductory Mechanics and Relativity
Physics 15a is Harvard's introductory mechanics course for physics concentrators and other strong-math students, covering Newtonian mechanics through special relativity. It's the entry point of the 15-series, the track for students who want physics done properly rather than as a requirement.
Fennie is independent and not affiliated with Harvard University. This is an unofficial study guide.
What makes it hard
The problems are the point and the pain: multi-step, idealized, and designed so that formula-matching fails. Limiting cases, clever coordinates, and approximations are the real skills, and the special relativity unit at the end asks students to trade hard-won intuition for spacetime reasoning just as the semester peaks.
What you'll cover
- • Kinematics and Newton's laws
- • Energy and momentum conservation
- • Rotational dynamics and angular momentum
- • Oscillations
- • Gravitation
- • Special relativity
The PHYSICS 15A study guide
How to study for Harvard PHYSICS 15A, step by step.
- 1
Solve symbolically, plug numbers last
Keep every problem in variables until the final line, then check limiting cases: mass to zero, angle to ninety. The limiting-case habit catches errors and is itself a skill 15a problems are built to reward.
- 2
Categorize problems by principle, not topic
Before any algebra, write whether the problem is forces, energy, momentum, or angular momentum and why. Selection is the exam skill; execution is just calculus.
- 3
Struggle first, solutions second
Give each hard problem a genuine attempt across two sittings before consulting any solution. The course builds problem-solving muscle, and muscle is built by lifting, not by watching.
- 4
Give special relativity its own runway
The relativity unit arrives late and replaces intuition with postulates. Start spacetime diagrams and gamma-factor problems two weeks before lecture lands there, because the reorientation takes time.
Today
Today's PHYSICS 15A plan
What a Fennie Daily Plan looks like for PHYSICS 15A. Yours is built from your own syllabus and adapts every day to your deadlines and progress.
First plan free, no card required. Fennie is independent and unaffiliated with your school.
FAQ
Is Physics 15a hard?
Yes. The problems are deliberately resistant to formula-matching and demand real problem-solving. Strong calculus and willingness to struggle productively are the prerequisites that matter.
Physics 15a or Physical Sciences 12a?
15a is the physics-concentrator track with harder problems and relativity; the PS courses serve pre-meds and life scientists. Choose by destination, not difficulty pride.
What math do I need for Physics 15a?
Solid single-variable calculus from day one, with multivariable (Math 21a level) helpful as the course progresses. The physics is never harder than the problem setups, but the math must be fluent.
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