Science a GoGo's Home Page Forums General Discussion Sci Fi Forum Orion, Mission to Alpha Centauri

1 kPa = .1450377 psi
10132kPa = 1472.959764 psi

we start with 100 psi... not 1472 psi

100 psi / .1450377 = 689.47 kPa
14.7 psi / .1450377 = 101

F = (689.47kPa-101kPa)*0.00064516m^2
F = 588.47kPa * 0.00064516m^2
F = 0.3796573052 N

not your result of



But the above is only the pressure thrust.

you still need to add the momentum or velocity thrust.

the part you left out (m*Ve) or (q*Ve)


F = (m × Ve) + (Pe - Pa) × Ae
air has a mass of 0.0807 lb / cu ft
0.0807 / 1728 = 0.000046701388 lbs / cu in
the area is 1 sq inch
so air at 6.828 atm has a mass of
6.828 X 0.000046701388 = 0.000318877077264 pound mass
0.000318877077264 pounds = 0.000144640209 kilograms
m = 0.000144640209 kilograms
100 pounds = 45.359237 kilograms
a = F/m
45.359237 kg / 0.000144640209 kg = 313600.466382069 m/s^2

F=(0.000144640209 * 313600.466382069 m/s^2)+ (Pe - Pa) × Ae
F=(45.359)+ (Pe - Pa) × Ae
F=(45.359)+ (689.47kPa-101kPa)*0.00064516m^2
F=(45.359)+ 588.47kPa * 0.00064516m^2
F= 45.359 + 0.3796573052
F = 45.738894305199934012421 N

45 kilograms = 99.208018 pounds

the momentum of the air leaving the tank through the nozzle has transfered to the pipe.