FULL REVIEW
Full Review: Simple Harmonic Motion — Calculus-Based
Review the essential ideas, relationships, and problem-solving tools for Simple Harmonic Motion.
TIME
45–60 minutes
BEST FOR
A complete topic review
FINISH WITH
A readiness check
After this full review, you'll be able to...
recall the essential ideas, apply them to representative problems, and determine what to study next.
Choose how you want to review
Topic Alignment
This bundle is aligned to the approved Physics Sensei topic specification below. Use it to recover the topic structure, reinforce key decisions, and confirm readiness for the next study task.
RESOURCE: Independent Physics Sensei Unit Review
UNIT: Mechanics • Unit MEC-U09
TOPIC: Simple Harmonic Motion
COURSE LEVEL: Calculus-Based
BEST USED
✓ After reading the chapter
✓ Before starting homework
✓ Before a quiz or exam
Your Review Plan
Complete these six stages in order. Each stage builds on the previous one and prepares you for the final readiness check.
6 Stages • Approximately 45-60 minutes.
Warm-Up Check
Before you begin, take a moment to see what you already remember. Do not worry about getting everything right. This is only a starting point.
ACTIVITY 1
Recall Activity 1
CALCULUS-BASED
Connect the force law to the equation of motion.
Reveal Answer
Why it works: The defining linear SHM equation has acceleration proportional to −x, with angular frequency squared equal to k/m.
ACTIVITY 2
Recall Activity 2
CALCULUS-BASED
Differentiate the position function carefully.
Reveal Answer
Why it works: Velocity is one quarter-cycle out of phase with displacement; acceleration is exactly opposite displacement.
ACTIVITY 3
Recall Activity 3
CALCULUS-BASED
Use the potential-energy picture near stable equilibrium.
Reveal Answer
Why it works: A smooth potential near a stable minimum has a leading quadratic term, producing a linear restoring force.
Ready to strengthen your understanding?
You've refreshed what you already know. Next, you'll reinforce the essential concepts that will help you solve problems with confidence. Need to see the learning path again?
Core Concepts
Let's rebuild the key ideas one step at a time. Focus on understanding the relationships before worrying about solving problems.
KEY CONCEPT 1
Restoring force and the SHM model
SHM is defined by d²x/dt² = −ω²x. For a spring-mass system, ω² = k/m. More generally, linearization about a stable equilibrium gives the same form when the leading restoring term is proportional to displacement.
d²x/dt² + ω²x = 0; spring: ω² = k/m; near a stable minimum, kₑ = d²U/dx² evaluated at equilibrium
Example: If U(x) ≈ U₀ + ½(18 N/m)x² near equilibrium, then small motion has ω = √(18/m).
Sensei Note: Do not call every back-and-forth motion SHM. The key test is whether the restoring force is approximately linear in displacement over the motion being modeled.
KEY CONCEPT 2
Amplitude, period, phase, displacement, velocity, and acceleration
Differentiating x(t) gives v(t) and a(t). Displacement and acceleration differ by π radians; velocity differs from displacement by π/2 radians. Phase-space and x-v-a graphs encode these relations without treating the three quantities as simultaneous maxima.
v = dx/dt = −Aω sin(ωt + φ); a = d²x/dt² = −Aω² cos(ωt + φ) = −ω²x
Example: For x = 0.040 cos(6t + π/3) m, v = −0.240 sin(6t + π/3) m/s and a = −1.44 cos(6t + π/3) m/s².
Sensei Note: Do not confuse amplitude with distance traveled in a cycle. One full cycle covers a path length 4A, while the amplitude is only A.
KEY CONCEPT 3
Energy, spring oscillators, and the simple pendulum
Energy conservation follows directly from the SHM equation. For a pendulum, sin θ ≈ θ converts θ¨ = −(g/L)sin θ into θ¨ + (g/L)θ = 0. This approximation is the mathematical reason the small-angle pendulum is simple harmonic.
d/dt[½m(dx/dt)² + ½kx²] = 0; pendulum: θ¨ + (g/L)θ ≈ 0 for |θ| ≪ 1 rad
Example: For m = 0.50 kg, k = 200 N/m, A = 0.080 m, at x = 0.040 m: U = 0.16 J, K = 0.48 J, and |v| ≈ 1.39 m/s.
Sensei Note: The simple-pendulum formula is a small-angle result. At large amplitude, the motion is periodic but not exactly simple harmonic and the period increases with amplitude.
Ready to apply these ideas?
You've reinforced the essential concepts. Now it's time to put them into practice by working through guided examples and building your problem-solving confidence. Need a quick reminder?
Guided Practice
Now it's time to apply what you've reviewed.
Work through each activity in order. The examples become gradually more challenging, and each one prepares you for the final readiness check.
PRACTICE 1
Worked Example
Identify equilibrium, choose the positive direction, and apply the restoring-force model.
Reveal Answer
Why it works: Compare the equation directly with x¨ = −ω²x.
PRACTICE 2
Guided Problem
Use the cycle relationships among x, v, a, T, f, and ω.
Reveal Answer
Why it works: Differentiate the position function first, then substitute t = 0 and preserve the phase sign.
PRACTICE 3
Independent Problem
Use energy or the pendulum model, and state the assumptions that make the model valid.
Reveal Answer
Why it works: The pendulum is approximately SHM only after linearizing sin θ about θ = 0.
Ready to check your understanding?
You've practiced the essential skills with guidance. Now it's time to solve a few short problems on your own and confirm you're ready to move forward. Need a quick reminder?
Confidence Check
You've rebuilt the key ideas and practiced them with guidance. Now try these short questions on your own to check your understanding before moving on.
QUICK CHECK 1
Restoring-force model check
Answer and justify in one sentence.
Reveal Answer
Why it works: The proportionality to −x produces sinusoidal motion with constant angular frequency.
QUICK CHECK 2
Cycle and phase check
Use the cycle, not memorized slogans.
Reveal Answer
Why it works: Maximum negative velocity occurs when sin(ωt) = 1.
QUICK CHECK 3
Energy and pendulum model check
State the model assumption with the answer.
Reveal Answer
Why it works: Only the small-angle approximation sin θ ≈ θ gives a constant-coefficient linear SHM equation.
How did it go?
You've checked your understanding. Take one final look at the essential ideas before deciding what to do next. Need a quick reminder?
Summary
Before moving on, take one final look at the most important ideas from this review.
KEY TAKEAWAY 1
Test the restoring law first
SHM requires a stable equilibrium and acceleration proportional to −displacement. For a spring, F = −kx and ω = √(k/m).
KEY TAKEAWAY 2
Read the cycle through phase relationships
Use ω = 2πf, x = A cos(ωt + φ), v = dx/dt, and a = −ω²x. At equilibrium speed is maximum; at turning points speed is zero.
KEY TAKEAWAY 3
Use energy and respect the small-angle limit
For an ideal spring, E = ½kA² is constant. A simple pendulum is approximately SHM only when sin θ ≈ θ is valid.
Ready for your next step?
You've reviewed the essential ideas one last time. Now choose the resource that best matches how confident you feel. Need a quick reminder?
Next Step
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