Answer:64.10 Btu/lbm
Explanation:
Work done in an isothermally compressed steady flow device is expressed as
Work done = P₁V₁ In { P₁/ P₂}
Work done=RT In { P₁/ P₂}
where P₁=13 psia
P₂= 80 psia
Temperature =°F Temperature is convert to °R
T(°R) = T(°F) + 459.67
T(°R) = 55°F+ 459.67
=514.67T(°R)
According to the properties of molar gas, gas constant and critical properties table, R which s the gas constant of air is given as 0.06855 Btu/lbm
Work = RT In { P₁/ P₂}
0.06855 x 514.67 In { 13/ 80}
=0.06855 x 514.67 In {0.1625}
= 0.06855 x 514.67 x -1.817
=- 64.10Btu/lbm
The required work therefore for this isothermal compression is 64.10 Btu/lbm
Answer:
yes
- electric and/or hybrid cars
- microwave ovens
- LED lighting
- low-power electronics
Explanation:
Advances in technology and changes in social organization have brought about reductions in energy use on many fronts.
- hybrid/electric vehicles have reduced transportation energy needs
- microwave ovens have reduced cooking energy needs
- LED lighting has reduced lighting energy needs
- low-power electronics have reduced the energy cost of technology and entertainment
- heat pumps and insulated windows have reduced energy needs for home heating and cooling
- zoning laws have reduced the need for travel to work and shopping areas
Answer:
eccentrcity of orbit is 0.22
Explanation:
GIVEN DATA:
Initial velocity of satellite = 8333.3 m/s
distance from the sun is 600 km
radius of earth is 6378 km
as satellite is acting parallel to the earth therefore![\theta angle = 0](https://tex.z-dn.net/?f=%20%5Ctheta%20angle%20%3D%200)
and radial component of given velocity is zero
we have![h = r_o v_r_o = 6378+600 =6.97*10^6 m](https://tex.z-dn.net/?f=%20h%20%3D%20r_o%20v_r_o%20%3D%206378%2B600%20%3D6.97%2A10%5E6%20m)
h = 6.97*10^6 *8333.3 = 58.08*10^9 m^2/s
we know that
![\frac{1}{r} =\frac{GM}{h^2} \times ( i + \epsilon cos\theta)](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7Br%7D%20%3D%5Cfrac%7BGM%7D%7Bh%5E2%7D%20%5Ctimes%20%28%20i%20%2B%20%5Cepsilon%20cos%5Ctheta%29)
![GM = gr^2 = 9.81*(6.37*10^6)^2 = 398*10^{12} m^3/s](https://tex.z-dn.net/?f=GM%20%3D%20gr%5E2%20%3D%209.81%2A%286.37%2A10%5E6%29%5E2%20%3D%20398%2A10%5E%7B12%7D%20m%5E3%2Fs)
so
![\frac{1}{6.97*10^6} =\frac{398*10^{12}}{(58.08*10^9)^2} \times ( i + \epsilon cos0)](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B6.97%2A10%5E6%7D%20%3D%5Cfrac%7B398%2A10%5E%7B12%7D%7D%7B%2858.08%2A10%5E9%29%5E2%7D%20%5Ctimes%20%28%20i%20%2B%20%5Cepsilon%20cos0%29)
solvingt for ![\epsilon)](https://tex.z-dn.net/?f=%20%5Cepsilon%29)
![\epsilon = 0.22)](https://tex.z-dn.net/?f=%5Cepsilon%20%3D%200.22%29)
therefore eccentrcity of orbit is 0.22
Answer:
a) 24 kg
b) 32 kg
Explanation:
The gauge pressure is of the gas is equal to the weight of the piston divided by its area:
p = P / A
p = m * g / (π/4 * d^2)
Rearranging
p * (π/4 * d^2) = m * g
m = p * (π/4 * d^2) / g
m = 1200 * (π/4 * 0.5^2) / 9.81 = 24 kg
After the weight is added the gauge pressure is 2.8kPa
The mass of piston plus addded weight is
m2 = 2800 * (π/4 * 0.5^2) / 9.81 = 56 kg
56 - 24 = 32 kg
The mass of the added weight is 32 kg.
Answer:
Explanation:
A smaller clearance volume means a higher compression. A higher compression means better thermal efficiency. However a compression ratio too high might be troublesome, as it can cause accidental ignition of the fuel-air mix. This is the reason why Otto cycle engines have lower compressions that Diesel engines. In a Diesel engine the mix ignites by compression instead of a spark.