Flight Science Worksheet

Name: ____________________ Date: ____________________

Back to learning activities · Open converter

1. Mach and temperature

Set Mach 2 in the converter, then enter each temperature. Record the results and explain the difference.

Conditionkm/hLocal sound speed, m/s
15°C, Mach 2
−56.5°C, Mach 2

Why does one Mach number correspond to different speeds?

2. Classify before comparing

AircraftPropulsionMissionSpeed evidence
SR-71
X-15

3. Make a traceable fact card

Aircraft: ____________________ Value and unit: ____________________

Source URL: ____________________________________________________

Event date: __________________ Source checked: __________________

Applicable conditions or remaining uncertainty:

4. Five-question check

  1. At Mach 2, is km/h higher at 15°C or −56.5°C? Why?
  2. Is standard-atmosphere mode live weather or a reference model?
  3. Is SR-72’s Mach 6 a measured world record or a public concept’s design target?
  4. Why explain the X-15 and SR-71 in different categories?
  5. What information should accompany a speed number in a citation?

Teacher / self-study answer key

Ideal dry-air model: a = √(1.4 × 287.05 × T), with T in kelvin; speed = Mach × a. At 15°C, sound speed is about 340.29 m/s and Mach 2 is about 2,450.10 km/h. At −56.5°C, these are about 295.07 m/s and 2,124.49 km/h.

  1. 15°C: warmer air has a higher local sound speed, so the same ratio gives a higher true airspeed.
  2. A reference model, not live weather. Altitude mode uses a 6.5°C/km decrease to 11 km, then −56.5°C to 20 km.
  3. A public concept’s design target, not a demonstrated flight record.
  4. X-15 is a rocket research aircraft; SR-71 is an air-breathing reconnaissance jet. Propulsion, mission and record categories differ.
  5. Aircraft/variant, source document, date, measurement or specification conditions, units and limitations. Keep event, page-update and source-check dates separate.

Fact-card answers vary by aircraft. Assess traceability and honest unknowns, rather than rewarding the largest number.

Sources: NASA Glenn: speed of sound · U.S. Standard Atmosphere, 1976 · NASA X-15

FastestPlanes · Educational reference model; not for flight planning.