Answer:
mevaporation=˙Qhfg=1. 8 kJ /s2269. 6 kJ /kg=0 . 793×10−3kg/ s=2. 855 kg /h
Explanation:
The properties of water at 1 atm and thus at the saturation temperature of 100C are hfg =2256.4 kJ/kg (Table A-4). The net rate of heat transfer to the water is ˙Q=0 . 60×3 kW=1 . 8 kWNoting that it takes 2256.4 kJ of energy to vaporize 1 kg of saturated liquid water, therate of evaporation of water is determined to be mevaporation=˙Qhfg=1. 8 kJ /s2269. 6 kJ /kg=0 . 793×10−3kg/ s=2. 855 kg /h
Answer:
diameter is 14.83 mm
Explanation:
given data
height = 2 mm
to find out
internal diameter
solution
we consider here material is glass and liquid is water and angle is zero if no capillary rise
we apply here capillary rise formula that is
Capillary rise h = 2T / [ r×ρ×g ] ....................1
put here r is radius and ρ = 1000 kg/m³, T = 72.7 ×
N/m all value in equation 1
Capillary rise h = 2T / [ r×ρ×g ]
r = 2T / [ h×ρ×g ]
d/2 = 2T / [ h×ρ×g ]
d/2 = 2( 72.7 ×
) / [ 2×
×1000×9.8 ]
d = 0.0148336 m
so diameter is 14.83 mm
Answer:
For uniaxial tension the objective is to minimize cost:
C = mCm= ALrCm where m is mass, A is the cross-section area, r is density, and Cm is cost per unit mass. For strength limited design: F/A ≤sy, and A ≥ F/sy To minimize C = (F/sy) LrCm= (FL)(rCm/sy), minimize the quantity (rCm/sy). Maximize the material index,M =sy/(rCm)
b. The objective is to minimize cost C = mCm= b2LrCm, where A = b2 is the cross-section for strength limited design. It is necessary to eliminate the variable b from the equation.
Now if A= b2
Then b=A/2
Therefore cost C= mCm=A/2.2LrCm
= ALrCm