mach
Jet speed unit
Mach is the ratio of an object's speed to the speed of sound in the surrounding medium.
Mach 1 is the speed of sound (about 767 mph at sea level); Mach 2 is twice that.
Aircraft traveling below Mach 1 are subsonic, above it supersonic: The jet broke Mach 3.
Named for physicist Ernst Mach, the term is conventionally capitalized, though lowercase appears in technical contexts.
Exceeding audio velocity
- transonicNear sound-speed velocity
- hypersonicFaster than Mach five
- velocityDirected rate of motion
- accelerationRate velocity changes
rapid · swift · lightning · meteoric · turbocharged · scorching · express · fleeting
Forced fluid stream
- fighterOne who engages in combat
- aircraftAirborne transportation vehicle
- aviationFlying or operating aircraft
- pilotOne who steers aircraft
turbojet · ramjet · scramjet · thrust · propulsion · throttle · airspeed · wind tunnel
Loud deep sound
- sonic boomShockwave's audible crack
- shockwavePropagating pressure disturbance
- compressionForcing into smaller space
- pressure waveMoving compression through medium
sound barrier · afterburner · turbulence · vibration · oscillation · wake · cone · nose cone
Philosophy demanding verifiable evidence
- empiricismKnowledge through observation
- philosophyStudy of fundamental truths
- relativityHow observers differ
- EinsteinByword for genius
influence · principle · sensation · perception · epistemology
Symbol representing quantity
- ratioComparative numerical relation
- calibrationAdjusting for measurement accuracy
- gaugeStandard of measurement
- instrumentationDesign of measuring devices
precision · indicator · scale · dial · anemometer · altimeter · tachometer · meter
supersonic
Exceeding audio velocity
- transonicNear sound-speed velocity
- hypersonicFaster than Mach five
- velocityDirected rate of motion
acceleration · rapid · swift · lightning · meteoric · turbocharged · scorching · express · fleeting · quick
jet
Forced fluid stream
- fighterOne who engages in combat
- aircraftAirborne transportation vehicle
- aviationFlying or operating aircraft
pilot · turbojet · ramjet · scramjet · thrust · propulsion · throttle · airspeed · wind tunnel · test flight
boom
Loud deep sound
- sonic boomShockwave's audible crack
- shockwavePropagating pressure disturbance
- compressionForcing into smaller space
pressure wave · sound barrier · afterburner · turbulence · vibration · oscillation · wake · cone · nose cone
positivism
Philosophy demanding verifiable evidence
- empiricismKnowledge through observation
- philosophyStudy of fundamental truths
- relativityHow observers differ
Einstein · influence · principle · sensation · perception · epistemology
number
Symbol representing quantity
- ratioComparative numerical relation
- calibrationAdjusting for measurement accuracy
- gaugeStandard of measurement
instrumentation · precision · indicator · scale · dial · anemometer · altimeter · tachometer · meter · reading
machmiles per hour
Speed unit, American roads
kilometers per hour · mph · kph · knots · ground speed
- washing machineAppliance for laundering textiles
- time machineDevice enabling temporal journeys
- vending machineAutomated product dispenser
- machine gunContinuous-fire arm
- answering machineTelephone message recorder
- slot machineCoin-operated gambling device
machine, machinery, machismo, machinist, machination, machinations, machinate, Mach number