Answer:
the maximum thermal efficiency is 29%
Explanation:
the maximum efficiency for a thermal engine that works between a cold source and a hot source is the one of a Carnot engine. Its efficiency is given by
Maximum efficiency= 1 - T2/T1
where
T2= absolute temperature of the cold sink (environment)= 20°C + 273 = 293
T2= absolute temperature of the hot source (hot water supply) = 140°C + 273 = 413
therefore
Maximum efficiency= 1 - T2/T1 = 1 - 293/413 = 0,29 =29%
Answer:
T = 858.25 s
Explanation:
Given data:
Reheat stage for a 100-mm-thick steel plate ( 7830 kg/m3, c 550 J/kg K, k 48 W/m K),
initial uniform temperature ( Ti ) = 200 c
Final temperature = 550 c
convection coefficient = 250 w/m^2 k
products combustion temp = 800 c
calculate how long the plate should be left in the furnace ( to attain 550 c )
first calculate/determine the Fourier series Number ( Fo )

= 0.4167 = 
therefore Fo = 3.8264
Now determine how long the plate should be left in the furnace
Fo = 
k = 48
p = 7830
L = 0.1
Input the values into the relation and make t subject of the formula
hence t = 858.25 s
Answer:
coupling is in tension
Force = -244.81 N
Explanation:
Diameter of Hose ( D1 ) = 35 mm
Diameter of nozzle ( D2 ) = 25 mm
water gage pressure in hose = 510 kPa
stream leaving the nozzle is uniform
exit speed and pressure = 32 m/s and atmospheric
<u>Determine the force transmitted by the coupling between the nozzle and hose </u>
attached below is the remaining part of the detailed solution
Inlet velocity ( V1 ) = V2 ( D2/D1 )^2
= 32 ( 25 / 35 )^2
= 16.33 m/s