Answer:
Explanation:
Given
Required
Convert to standard form
From laws of indices
So, is equivalent to
Hence, the standard form of is 
Answer:
t = 25.10 sec
Explanation:
we know that Avrami equation
here Y is percentage of completion of reaction = 50%
t is duration of reaction = 146 sec
so,
taking natural log on both side
ln(0.5) = -k(306.6)
for 86 % completion
t = 25.10 sec
Answer:
0.0406 m/s
Explanation:
Given:
Diameter of the tube, D = 25 mm = 0.025 m
cross-sectional area of the tube = (π/4)D² = (π/4)(0.025)² = 4.9 × 10⁻⁴ m²
Mass flow rate = 0.01 kg/s
Now,
the mass flow rate is given as:
mass flow rate = ρAV
where,
ρ is the density of the water = 1000 kg/m³
A is the area of cross-section of the pipe
V is the average velocity through the pipe
thus,
0.01 = 1000 × 4.9 × 10⁻⁴ × V
or
V = 0.0203 m/s
also,
Reynold's number, Re = 
where,
ν is the kinematic viscosity of the water = 0.833 × 10⁻⁶ m²/s
thus,
Re = 
or
Re = 611.39 < 2000
thus,
the flow is laminar
hence,
the maximum velocity = 2 × average velocity = 2 × 0.0203 m/s
or
maximum velocity = 0.0406 m/s
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.
