Question

A fighter plane is flying overhead at mach 1.20. What angle does the wave front of the shock wave produced make relative to the plane's direction of motion (in degrees)?

Answer 1

Answer: 56.44°

Explanation:

Given:

• Let u represent the current speed of the plane, 1.2 Mach

Converting to SI Units (m/s):

= (1.2 mach)(340 ms^-1 / 1 Mach)

u  = 408 m/s

• Speed of sound in air, v = 340 m/s

Find:

• Angle the wave front of the shock wave relative to the plane's direction of motion, θ

We have, sinθ = speed of sound / speed of object

               sinθ = v / u

                   θ = sin^-1 (v / u)  

                      = sin^-1 (340 / 408)

                   θ = 56.44°