College Board-Aligned Original Notes

AP Physics 2: Algebra-Based Unit 14 Topic 3: Sound

Sound is a mechanical wave produced by pressure variations traveling through a medium.

Unit 14: Waves, Sound, and Physical Optics. College Board exam weighting listed for this unit: 12%-15% of exam score.

What to Know

Sound requires a material medium and cannot travel through vacuum.
Pitch relates to frequency, while loudness relates to intensity and amplitude.
Sound speed depends on properties of the medium.
Always connect this topic back to the larger unit: Waves, Sound, and Physical Optics.

Detailed Notes

Sound belongs to Unit 14: Waves, Sound, and Physical Optics. Sound is a mechanical wave produced by pressure variations traveling through a medium. Start by identifying the system, the field or interaction involved, and which conservation law or model applies.

Key relationships: Sound requires a material medium and cannot travel through vacuum. Pitch relates to frequency, while loudness relates to intensity and amplitude. Sound speed depends on properties of the medium.

Model to use: Draw compressions and rarefactions in air and relate spacing to wavelength. A clear AP Physics 2 model should label directions, signs, units, and the physical meaning of each variable.

AP-style move: For sound questions, identify whether the wave is longitudinal and which medium sets the speed. For free-response work, show the governing principle first, then connect the mathematical result back to the physical situation.

Key Vocabulary

Sound wave

A mechanical pressure wave traveling through a medium.

Longitudinal wave

A wave whose disturbance is parallel to its direction of travel.

Compression

Region of higher pressure in a longitudinal wave.

Rarefaction

Region of lower pressure in a longitudinal wave.

Sound intensity

Power carried by sound per unit area.

Quick Practice

How would you explain Sound in one or two AP-style sentences?

Name the concept, apply it to a specific example or source, and explain the reasoning that connects the evidence to your answer.

Official Alignment

Reference and Attribution

AP Physics 2 concept reference: AP Physics 2: Concise Summary Notes by IITian Academy. EduCompanion used this source as a topic checklist and conceptual reference, then rewrote the study notes in original wording.

AP Physics 2: Concise Summary Notes