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:
a) Mechanical efficiency (
)=63.15% b) Temperature rise= 0.028ºC
Explanation:
For the item a) you have to define the mechanical power introduced (Wmec) to the system and the power transferred to the water (Pw).
The power input (electric motor) is equal to the motor power multiplied by the efficiency. Thus,
.
Then, the power transferred (Pw) to the fluid is equal to the flow rate (Q) multiplied by the pressure jump
. So
.
The efficiency is defined as the ratio between the output energy and the input energy. Then, the mechanical efficiency is 
For the b) item you have to consider that the inefficiency goes to the fluid as heat. So it is necessary to use the equation of the heat capacity but in a "flux" way. Calling <em>H</em> to the heat transfered to the fluid, the specif heat of the water and
the density of the water:
[/tex]
Finally, the temperature rise is:

Answer:
the width of the turning roadway = 15 ft
Explanation:
Given that:
A ramp from an expressway with a design speed(u) = 30 mi/h connects with a local road
Using 0.08 for superelevation(e)
The minimum radius of the curve on the road can be determined by using the expression:

where;
R= radius
= coefficient of friction
From the tables of coefficient of friction for a design speed at 30 mi/h ;
= 0.20
So;



R = 214.29 ft
R ≅ 215 ft
However; given that :
The turning roadway has stabilized shoulders on both sides and will provide for a onelane, one-way operation with no provision for passing a stalled vehicle.
From the tables of "Design widths of pavement for turning roads"
For a One-way operation with no provision for passing a stalled vehicle; this criteria falls under Case 1 operation
Similarly; we are told that the design vehicle is a single-unit truck; so therefore , it falls under traffic condition B.
As such in Case 1 operation that falls under traffic condition B in accordance with the Design widths of pavement for turning roads;
If the radius = 215 ft; the value for the width of the turning roadway for this conditions = 15ft
Hence; the width of the turning roadway = 15 ft
...simplify devices, reducing weight and the chance of failure.
Answer:
6.5 × 10¹⁵/ cm³
Explanation:
Thinking process:
The relation 
With the expression Ef - Ei = 0.36 × 1.6 × 10⁻¹⁹
and ni = 1.5 × 10¹⁰
Temperature, T = 300 K
K = 1.38 × 10⁻²³
This generates N₀ = 1.654 × 10¹⁶ per cube
Now, there are 10¹⁶ per cubic centimeter
Hence, 