Question

A supersonic jet travelling at Mach $3.00$ at an altitude of $20000m$ is directly over a person at time $t=0$ as shown in Fig $2.89$
How long will it be before the person encounters the shock wave?

Answer 1

Let speed of sound in air be $335m/s$.

$sinq=v/v_s$ here $v_s$ is the speed of Mach $3.00$

$sinq=335/3\left(335\right)$

$q={19.5}^o$

$tanq=h/x$

$tan19.5°=20000/x$

$x=5.66\times 104meters$

$v=Dx/Dt$

$3\left(335\right)=5.66\times 104/Dt$

$t=56.3sec$