Answer a) roof equilibrium temperature is 400K
Explanation:
The roof surface is sorrounded by ambient air whose temperature is 300K and which has a convective coefficient h of 10W/m2-K.
This means that heat will be conducted to the roof from the air around at an heat Flux of 300K x 10W/m2-K = 3000w/m2
For a clear solar day with solar heat Flux of 500W/m2, total heat Flux on roof will be
Q = 500 + 3500 = 3500W/m2
Q = h(Tr-Ta)
Ts is temperature of roof,
Ta is temperature of air
3500 = 10(Tr - 50)
350 = Tr - 50
Tr = 400k
Answer b): roof equilibrium temperature will be 350K
Explanation:
At night total heat Flux is only due to hot ambient air sorrounding the surface of the roof.
Q = 3000W/m2
Q = h(Tr-Ta)
3000 = 10(Tr-50)
300 = Tr - 50
Tr = 350K
Lo siento, no sé qué estás diciendo.
Answer: hydraulic retention time,τ=28.67 hours
Explanation:
The hydraulic retention time τ (tau), is given as The volume of the settling tank(V) divided by the influent flowrate(Q)
τ =V/Q
But Volume is not known and is given as
Volume = surface area x depth of the tank
= 8000 ft² X 12 ft
= 96,000 ft³
Also, the influent flow rate is in mgd ( million gallons per day), we change it to ft³/sec so as to be in same unit with the volume in ft³
1 million gallons/day = 1.5472286365101 cubic feet/second
0.6mgd = 1.5472286365101 cubic feet/second x 0.6
=0.93cubic feet/second
τ =V/Q
96,000 ft³/0.93 ft³/sec
τ=103,225.8 secs
changing to hours
103,225.8 /3600 =28.67 hours
The hydraulic retention time =28.67 hours
Answer:A rear disc/drum parking brake uses the inside of each rear wheel hub and rotor assembly as a parking brake drum
Explanation: