AP Physics 1 ›  Unit 7

Unit 7 Oscillations

Everything that repeats. Four episodes covering the physics of springs, pendulums, and any system where a restoring force brings an object back to equilibrium — over and over again.

📋 5–8% AP Exam Weighting🕐 ~5–10 Class Periods📺 4 Episodes✅ Progress Check 7
AP Physics 1 Home

Episode Guide — Season 7

EP.7.1

Defining Simple Harmonic Motion

SHM is periodic motion driven by a restoring force proportional to displacement. Springs and pendulums both qualify — every oscillation starts here.

F_restore ∝ −xEquilibrium positionRestoring forceF = −kx
🕐 1–2 daysOpen →
EP.7.2

Frequency and Period of SHM

How long does one oscillation take? T and f depend on the system's properties — mass and spring constant, or pendulum length — but never on amplitude.

T = 1/fT_s = 2π√(m/k)T_p = 2π√(L/g)Amplitude independence
🕐 2–3 daysOpen →
EP.7.3

Representing and Analyzing SHM

Displacement, velocity, and acceleration all oscillate sinusoidally — but out of phase with each other. Graphs unlock the full picture of what's happening at any instant.

x(t) = A cos(2πft)v_max = 2πfAx and a are anti-phaseGraph reading
🕐 2–3 daysOpen →
EP.7.4

Energy of Simple Harmonic Oscillators

Total mechanical energy in SHM is constant. KE and PE trade places every half-cycle. At maximum displacement, all energy is potential. At equilibrium, all energy is kinetic.

E = ½kA²KE + PE = constantv_max at x = 0Energy bar charts
🕐 2–3 daysOpen →
🎓 AP Classroom — Progress Check 7
Four FRQ types: Mathematical Routines, Translation Between Representations, Experimental Design, and Qualitative/Quantitative Translation. The TBR question frequently uses SHM graphs.
Go to AP Classroom →