A common belief is that a hole in a jet plane can suck a person out. On an episo

Question

A common belief is that a hole in a jet plane can suck a person out. On an episode of the popular TV series Myth Busters, hosts Adam and Jaime attempted to determine whether this is possible. According to the hosts' experiment, such an event cannot happen (that is, they "busted" the myth). But did they need to perform the experiment As a science advisor to the show, Adam and Jaime ask you to perform a crude calculation to test the myth. A typical jet plane travels at 532 mph at a cruising altitude of 25500 ft. The windows on a jet plane measure 14.0 in * 14.0 in. Calculate the force exerted on such a window as the plane flies at 25500 ft. above the sea level. (Assume the density and pressure of air at 25500 feet is 0.562 kg/m^3 and 382 mbar but the interior of the plane remains pressurized to atmospheric pressure, that is, 1 atm.) Calculate the fractional difference between this force and the weight w_man of a typical adult male (185 lb). F/w_man = How would you respond to Adam and Jaime

Explanation / Answer

(a)

given that

velocity v = 532 mph = 532*.44704 = 237.82 m/s

sides of the window = 14 in = 0.356 m

pressure at height Po = 382 mbar = 38200 Pa

pressure in airplane Pa = 1 atm = 101325 Pa

density rho = 0.562 kg/m^3

pressure difference between the inside and outside of the plane

dP = 1/2*rh0*v^2 + (Pa-Po)

dP = 1/2*0.562*(237.82)^2 + (101325-38200)

dP = 15892.90+63125 = 79017.90 Pa

we know that

dP = F/A

where F = net force

A = area = (0.356)^2 = 0.126736 m^2

so F = dP*A = 79017.90*0.126736

F = 10014.41 N

F = 2251.329 lbs

(b)

F/Wman = 2251.329 / 185

F/Wman = 12.169

(c)

my calculation does not prove that such event cannot happen , you need to perform the experiment.

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.