In: Physics
*Please answer all three parts
Three Part Question: X. (A) NASA Atmospheric Mission balloons use helium that expands to almost 1 million cubic meter at the top of the atmosphere where pressure is 0.003 atm only. Even though it takes about 2.5 hours to get to this altitude, it is assumed that the rise is fast enough to be considered as adiabatic. Find the initial volume of the helium at the ground level. (Helium is a mono-atomic gas). (B) If the initial temperature of the gas was 15 degree celsius what is the temperature of the gas at the top? Ignore real atmospheric temperature changes. (C) What is the change in internal energy of the gas?
*Please provide steps, explanations, and formulas.
*Explain to me as if I know nothing
*I am genuinly trying to learn and understand. Please and thank you.
given
V2 = 1 million cubic meter
= 1018 m3
P2 = 0.003 atm
= 1.67 for mono
atomic gas
a )
using P V
P1 V1
=
P2 V2
V1
= (
P2 V2
/
P1 )
= ( 0.003 x 1018x 1.67 )
the initial volume of the helium at the ground level is V1 = 3 x 1016 m/sec
b )
T1 = 15oC
= 288 K
T V
-1 =
constant
T1 V1
-1 =
T2 V2
-1
T2 = T1 ( V1 / V2
)
-1
= 288 x ( 3 x 1016 / 1018 )1.67-1
the temperature of the gas at the top is T2 = 27.4 K
or
T2 = 27.4 - 273
the temperature of the gas at the top is T2 = - 245.5oC
c )
dU = dQ - dW
dQ = 0 for adiabatic process
dU = dW
= ( P1 V1 - P2 V2 )
/
- 1
= R ( T1 - T2 ) / (
- 1)
= 8.314 x 260.6 / 1.67 - 1
the change in internal energy of the gas is dU = - 3233.77 J