Physics Waves Sound

λ = ?

λ= Distance/Cycles

V = ? (universal)

V = λF

V = ?

V = λ/period

V = ? (on a string)

V = =√Ft/p

F= ?

F = Cycles/Time

T = ? (period)

T = time/ctcke

Match # = ?

Match# = Vobject/Vsound

Relationship between period (T) and frequency (F) equations

T = 1/

Vsound in air = ?

Vsound = 331.4m/s + 0.606m/s/*C T

Fobserver = ? (doppler)

Fobserver = (Vsound/Vsound-+Vsource)Vsource (- approaching, + passing)

Decibels

• Definition: What do they represent?

• Scale Type: Why do we use this math style?

• Baseline (0 dB): What does zero mean?

• The "+3 dB" and "+10 dB" Rules: What do these shifts mean physically?

• Definition: A relative unit expressing sound intensity compared to the human hearing threshold.

• Scale Type: Logarithmic. It compresses massive, trillions-wide ranges into a simple 0–120 scale.

• Baseline (0 dB): The quietest sound a healthy human ear can detect ($1 \times 10^{-12} \text{W/m}^2$). Not absolute silence.

• The Rules:

• +3 dB = Physical wave power doubles ($\times 2$).

• +10 dB = Physical wave power tenfolds ($\times 10$); human ears perceive this as twice as loud.

Sound Intensity

• Definition: What physically is it?

• Unit: How is it measured?

• Scale Type: How do the numbers scale?

• Range: What is the span of human hearing on this scale?