SPPA 4030 Speech Science1 Physical Quantities GOOD LINK sandUnitIntroduction.html

SPPA 4030 Speech Science2 Physical Quantities  Base quantities vs. Derived quantities

SPPA 4030 Speech Science3 Base or Fundamental quantities  Quantities that must be measured  Base measures from which all others are derived

SPPA 4030 Speech Science4 Selected Base Quantities 1. Distance or Length (l) 2. Mass (m) 3. Time (t)

SPPA 4030 Speech Science5 Systems of Measure English system: fps system F: foot P: pound S: second Metric system cgs system c: centimeters g: grams s: seconds Metric system (System International) mks system m: meter k: kilogram s: second

SPPA 4030 Speech Science6 What is the mass of speech structures? Vocal folds ~ 2 grams combined!! Lips ~ grams each Tongue ~ 150 grams

SPPA 4030 Speech Science7 What are typical distances moved by speech structures?

SPPA 4030 Speech Science8 What is the typical duration of speech events?

SPPA 4030 Speech Science9 Scalar vs. Vector quantities Scalar quantities Has only a magnitude Vector quantities Includes more than one piece of information i.e. Magnitude AND direction

SPPA 4030 Speech Science10 Area and Volume Area  2-dimensional  distance 2 Volume  3-dimensional  distance 3 l l l l l

11 Displacement  Displacement is a change in position  Is a vector quantity Has a magnitude (basic quantity of length) Has a direction Jaw vertical position Time

SPPA 4030 Speech Science12 Velocity (v)  Rate at which a quantity changes it’s value v = x/t where v = velocity x = distance t = time  May be expressed as average velocity instantaneous velocity  Velocity units m/sec (SI) cm/sec miles/hour  Velocity vs. speed  Volume velocity or flow

SPPA 4030 Speech Science13 Velocity (v)

SPPA 4030 Speech Science14 Acceleration (a)  Rate of change in velocity ‘speeding’ up or positive acceleration ‘slowing’ down or negative acceleration a = v/t where a = acceleration v = velocity t = time May be expressed as average acceleration instantaneous acceleration Acceleration units m/sec 2 (SI)

SPPA 4030 Speech Science15

SPPA 4030 Speech Science16 Force (F)  Is a push or a pull on an object F = M*a where F = force M = mass a = acceleration Force ↑ (or ↓) ↑ (or ↓) mass ↑ (or ↓) acceleration Force units Newton (SI) dyne

SPPA 4030 Speech Science17 Pressure (E or P)  Force distributed over an area E = F/A where E = pressure F = force A = area (x 2 ) Pressure units Pascal (SI) dyne/cm 2

18 = area = force Ways to increase Pressure

SPPA 4030 Speech Science19 Work (W) Force applied over a given distance W = F*x where W = work F = force x = distance Work ↑ (or ↓) ↑ (or ↓) force ↑ (or ↓) distance Work units Joule (SI) Erg Footpound

SPPA 4030 Speech Science20 Power (P) Power = rate at which work is done Power (P) P = W/t where P = Power W = work t = time Power units Watt (SI) horsepower

SPPA 4030 Speech Science21  Area over which power is focused  Intensity is to power what pressure is to force I = P/A where I = Intensity P = Power A = area Intensity (I) Intensity units watt/cm 2

SPPA 4030 Speech Science22 Resistance  acoustic or aerodynamic resistance = pressure/flow  In electrical world Ohm’s Law R=E/I where R= resistance E=voltage I=electric current Note: voltage is an electric analog to pressure