A heat engine operating between energy reservoirs at 20?c and 600?c has 30% of the maximum possible efficiency.
1 answer:
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Answer:
a) - 72.5°c
b) pressure = 3625.13 Pa
c) density = 0.063 kg/m^3
d) it is a subsonic aircraft
Explanation:
a) Determine Temperature
Temperature at 19.5 km ( 19500 m )
T = -131 + ( 0.003 * altitude in meters )
= -131 + ( 0.003 * 19500 ) = - 72.5°c
b) Determine pressure and density at 19.5 km altitude
Given :
Po (atmospheric pressure at sea level ) = 101kpa
R ( gas constant of air ) = 0.287 KJ/Kgk
T = -72.5°c ≈ 200.5 k
pressure = 3625.13 Pa
hence density = 0.063 kg/m^3
attached below is the remaining part of the solution
C) determine if the aircraft is subsonic or super sonic
Velocity ( v ) = =
= 283.8 m/s
hence it is a subsonic aircraft
Answer:
1
The mass of the Potassium-40 is
2
The Dose per year in Sieverts is
Explanation:
From the question we are told that
The isotopes of potassium in the body are Potassium-39, Potassium-40, and Potassium- 41
Their abundance is 93.26%, 0.012% and 6.728%
The mass of potassium contained in human body is per kg of the body
The mass of the first body is
Now the mass of potassium in this body is mathematically evaluated as
substituting value
The amount of Potassium-40 present is mathematically evaluated as
0.012% * 0.024
The dose of energy absorbed per year is mathematically represented as
Where E is the energy absorbed which is given as
Substituting value
The Dose in Sieverts is evaluated as