Mach Number Formula:
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Definition: This calculator determines the Mach number (ratio of object's speed to speed of sound) at a given altitude based on velocity, temperature, and atmospheric properties.
Purpose: Essential for aeronautical engineering, aviation, and aerospace applications to determine aircraft speed relative to the speed of sound at different altitudes.
The calculator uses the formula:
Where:
Explanation: The Mach number is calculated by dividing the object's velocity by the speed of sound in the given atmospheric conditions.
Details: Mach number is critical for understanding compressibility effects, shock waves, and aerodynamic heating that occur when approaching and exceeding the speed of sound.
Tips: Enter the velocity in m/s, temperature at altitude in Kelvin (default 288.15K ≈ 15°C at sea level), γ (default 1.4 for air), and R (default 287 J/kg·K for air). All values must be > 0.
Q1: What is the significance of Mach 1?
A: Mach 1 represents the speed of sound. Aircraft performance changes significantly as they approach and exceed this speed.
Q2: How does temperature affect Mach number?
A: The speed of sound increases with temperature, so at higher temperatures, the same velocity results in a lower Mach number.
Q3: What are typical Mach numbers for aircraft?
A: Commercial jets cruise at Mach 0.7-0.9, while supersonic aircraft exceed Mach 1. The Concorde flew at Mach 2.
Q4: Why use Kelvin for temperature?
A: Kelvin is an absolute temperature scale required for thermodynamic calculations where zero means absolute zero.
Q5: How does altitude affect Mach number?
A: At higher altitudes, temperature decreases, reducing the speed of sound. Thus, an aircraft flying at the same true airspeed will have a higher Mach number at altitude.