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When iron rusts in air, the following reaction occurs. What is the heat of formation of Iron(III) oxide?
4Fe(s)+3O2(g)=2Fe2O3(s) Delta H= -1643 KJ
In a pipe of 400mm and 900m length an oil of specific gravity 0.75 is flowing at the rate of 0.5Rm³/s find
1) Heat lost due to friction and
2) power required viscosity of oil as 0.3 Stokes.
Take kinematic viscosity of oil as 0.3stroke.
3. Concrete sidewalks are always laid in sections, with gaps between each section. For example, a drawing showing three identical 2.4 m sections, the outer two of which are against immovable walls. The two identical gaps between the sections are provided so that thermal expansion will not create the thermal stress that could lead to cracks. Calculate the minimum gap width necessary to account for an increase in temperature of 32 °C.
1. On the Rankine temperature scale, which is sometimes used in engineering applications, the ice point is at 491.67 °R and the stem point is at 671.67 °R.
a.) Determine the relationship between the Rankine and Fahrenheit temperature scales.
b.) A healthy person has an oral temperature of 98.67 °F. Calculate what would this reading be on the Rankine temperature scale.
2. Two identical thermometers made of Pyrex glass contain, respectively, identical volumes of mercury and methyl alcohol. If the expansion of the glass is taken into account, calculate how many times greater is the distance between the degree marks of the methyl alcohol thermometer than the distance on the mercury thermometer.
A steam enters a boiler at 3.42 bar, specific volume of 0.567 m3/kg, specific internal energy of
1892kJ/kg at velocity of 5 m/s. At rate 3 kg/s, th steam exit with 755 kN/m2, specific volume
of 0.892 m3/kg,specific internal energy of 2014 kJ/kg and velocity of 35 m/s. The boiler's exit
is 2m higher than the entrance. Calculate the heat transfer in kW and state either it is into or
out of the system.
An air occupies in the tank with pressure and volume of 6.5 bar and 0.37 m3 at 48 °C.After
an isobaric expansion, the volume increased to 0.42 m3. Determine the final temperature in
unit °C and the mass of the gas.
A piston of radins R=20 cm is free to move without friction inside a vertical cylinder filled with water and having the same diameter as that of the piston. The piston that floats at the surface of water is traversed by a hollow vertical straw with a radius r =1 cm Caleulate the height of water in the straw if the piston weighs 1250 N. P-1000 Ka/m3
A combustion engine is to be used for gas compressor in the cylinder. Initial expansion,internal energy is 1000kJ/kg. At the end of the process, the internal energy has been decreased by 700kJ/kg. Calculate the heat transfer if the work done to the system is
0.2MJ/kg and state either the heat is rejected or transferred to the system.
Calculate the heat required to convert 2kg of ice at -12°c to steam at 100°c. L for ice= 336000j/kg, L for steam= 2260000. C for ice = 2100j/kg/k
With a 3-fold increase in the radius of the circular orbit of an artificial Earth
satellite, the period of its rotation increases by 6 times. How many times will
the satellite's orbital speed change?
