Answer:
<em>d. floor spans exceed that which is economical with site-cast or hollow-core slabs and exceed 60 feet.</em>
<em></em>
Explanation:
<em>
Double tee slabs are prestressed concrete castings usually about 100 m to 150 m long</em>. <em>They are usually used in the construction industry in structures requiring a long floor span (or roof span) exceeding 60 feet in length, that is required to bear additional load (additional load carrying capability</em>). Double tee slabs are usually employed in construction because they shorten construction time. reduce congestion at the construction site, and also reduce construction cost.
<em>They are the required choice in construction when the cost of site casting or hollow-core slabs is no longer economical due to the length of the structure exceeding 60 feet.</em>
Answer: False
Explanation: For implementation of the safety and the health program, there is high requirement of the employees because they are the people who will participate in the program and can make it successful.
Apart from the management and the leader, who are there to manage the program and lead the program as head by taking responsibility of other respectively, employees participation is required.Employees are referred as the people who will do the activities and also teach other about it.Thus, the statement in question is false.
Answer:
1141
7.2
Explanation:
The evaporator Temperature T1 = -10°C
h1 = 244.55kj/kg
S1 = 0.93782kj/kg
The enthalpy at second state from given condenser pressure from super heated refrigerant table
P2 = 600
S2 = S1
h2 = 267.19kj/kg
Enthalpy at 3 and 4 from condenser pressure
h3 = h4 = 81.5kj/kg
To get cooling load
QL = m(h1-h4)
M= 7
= 7(244.55-81.5)
= 7(163.05)
= 1141.35kw = 1141KW
COP
= h1-h4/h2 -h1
= 244.55-81.5/267.19-244.55
= 163.05/22.64
= 7.2
Answer:
Fatigue lifetimes will be ranked as B>A>C
Explanation:
Start by calculating the mean stress for all samples
σa= (σamax + σamin)/2 = (450 - 350)/2 = 50MPa
σb= (σbmax + σbmin)/2 = (400 - 300)/2 = 50MPa
σa= (σcmax + σcmin)/2 = (340 - 340)/2 = 0MPa
Now calculate the stress amplitudes of all three samples
σa= (σamax - σamin)/2 = (450 + 350)/2 = 400MPa
σb= (σbmax - σbmin)/2 = (400 + 300)/2 = 350MPa
σc= (σcmax - σcmin)/2 = (340 + 340)/2 = 340MPa
The mean stress of samples A and B is the same which is higher than sample C. Hence samples A and B will have a higher fatigue life than sample C. However, the higher stress amplitude means lower fatigue life, hence, sample B will have a higher fatigue life than sample A. So the order will be B> A> C.
Attached picture shows the justification using and S- N plot.