ข้อสอบปี 1996
A hot -air balloon is floating in the atmosphere having temperature
and pressure
A burner was turned on and the temp. inside the ballon was increased from
to
. Assume
that the Volume
of the balloon doesn't change and the pressure inside balloon is
, the
same as the atmosphere pressure .When the Temp. increased from
to
,the mole of the
air inside it decreased from
to
.These quantities are expressed as
![n_{0} = [?]](/forums/Sources/latex/pictures/b74d36175071da6cdd4bca0e9d1922b0.png "n_{0} = [?]")
and
![n_{1} = [?]](/forums/Sources/latex/pictures/43bf2b2a77cba798d6399f20f242f2e6.png "n_{1} = [?]")
in term of R,Pressure ,Volume and Temperature. .If one denotes the mass of the air per mole by
and the gravitational acceleration by
, the climbing force exerted upon the ballon is the
resultant force of buoyancy
received by the ballon and the gravity
of
the air inside the balloon .
This climbing force of the original air per 1 mol (
)
,is written as [? ]
using
and
Supposing that
and
the climbing force
of the original air per 1 mol is able to lift a body having mass = [? ]kg
The Volume of the air of a mole is approximately 0.025
if
and
. This means that the volume of the balloon must exceed [?]
so that it lifts a body having mass 100 kg including the balloon itself.
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