Answer:
(b)False
Explanation:
Given:
Prandtl number(Pr) =1000.
We know that 
Where 
is the molecular diffusivity of momentum
is the molecular diffusivity of heat.
Prandtl number(Pr) can also be defined as
Where 
is the hydrodynamic boundary layer thickness and 
is the thermal boundary layer thickness.
So if Pr>1 then hydrodynamic boundary layer thickness will be greater than thermal boundary layer thickness.
In given question Pr>1 so hydrodynamic boundary layer thickness will be greater than thermal boundary layer thickness.
So hydrodynamic layer will be thicker than the thermal boundary layer.
Answer:
the crown is false densty= 12556kg/m^3[/tex]
Explanation:
Hello! The first step to solve this problem is to find the mass of the crown, this is found using the weight of the crown in the air by means of the equation for the weight.
W=mg
W=weight(N)=31.4N
M=Mass
g=gravity=9.81m/S^2
solving for M
m=W/g
The second step is find the volume of crown remembering that when an object is weighed in the water the result is the subtraction between the weight of the object and the buoyant force of the water which is the product of the volume of the crown by gravity by density of water
Where
F=weight in water=28.9N
m=mass of crown=3.2kg
g=gravity=9.81m/S^2
α=density of water=1000kg/m^3
V= crown´s volume
solving for V
finally, we remember that the density is equal to the index between mass and volume
To determine the density of the crown without using the weight in the water and with a bucket we can use the following steps.
1.weigh the crown in the air and find the mass
2. put water in a cylindrical bucket and measure its height with a ruler.
3. Put the crown in the bucket and measure the new water level with a ruler.
4. Subtract the heights, and find the volume of a cylinder knowing the difference in heights and the diameter of the bucket, in order to determine the volume of the crown.
5. find density by dividing mass by volume
Answer:
The work of the cycle.
Explanation:
The area enclosed by the cycle of the Pressure-Volume diagram of a Carnot engine represents the net work performed by the cycle.
The expansions yield work, and this is represented by the area under the curve all the way to the p=0 line. But the compressions consume work (or add negative work) and this is substracted fro the total work. Therefore the areas under the compressions are eliminated and you are left with only the enclosed area.
Answer:
1. They needed to develop multiple components in software programs.
2. The ability to overlap the development to be more evolutionary in nature.
3. The need to be more risk-averse or the unwillingness to take risks led to the use of a spiral model.
Explanation:
Software development life cycle (SDLC) can be defined as a strategic process or methodology that defines the key steps or stages for creating and implementing high quality software applications.
In SDLC, a waterfall model can be defined as a process which involves sequentially breaking the software development into linear phases. Thus, the development phase takes a downward flow like a waterfall and as such each phase must be completed before starting another without any overlap in the process.
An incremental model refers to the process in which the requirements or criteria of the software development is divided into many standalone modules until the program is completed.
Also, a spiral model can be defined as an evolutionary SDLC that is risk-driven in nature and typically comprises of both an iterative and a waterfall model. Spiral model of SDLC consist of these phases; planning, risk analysis, engineering and evaluation.
<em>What motivated software engineers to move from the waterfall model to the incremental or spiral model is actually due to the following fact;</em>
- They needed to develop multiple components in software programs.
- The ability to overlap the development to be more evolutionary in nature.
- The need to be more risk-averse or the unwillingness to take risks led to the use of a spiral model.
