6. PVC boxes are primarily used in new construction because it is simple to

Which basic principle influences how all HVACR systems work?

bezimeni [28]

Answer:

B) An increase in pressure can lower the boiling point of a liquid and change the temperature at which it turns to a gas.

Explanation:

B) An increase in pressure can lower the boiling point of a liquid and change the temperature at which it turns to a gas.

6 0

3 years ago

The statement that is NOT true about the concept of a boundary layer on an object is: a. the Reynolds number is greater than uni

Ilya [14]

Answer:

Option E

Explanation:

All the given statements are true except the velocity gradients normal to the flow direction are small since these are not normally small. It's true that viscous effects are present only inside the boundary layer and the fluid velocity equals the free stream velocity at the edge of the boundary layer. Moreover, Reynolds number is greater than unity and the fluid velocity is zero at the surface of the object.

5 0

2 years ago

What motivated software engineers to move from the waterfall model to the incremental or spiral model

scoray [572]

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.

What motivated software engineers to move from the waterfall model to the incremental or spiral model is actually due to the following fact;

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.

6 0

3 years ago

A rigid tank contains 2 kg of N2 and 4 kg of Co2 at temperature of 25 C and 1 MPa. Find the partial pressure of each gas respect

lions [1.4K]

Answer: Partial pressures are 0.6 MPa for nitrogen gas and 0.4 MPa for carbon dioxide.

Explanation: Dalton's Law of Partial Pressure states when there is a mixture of gases the total pressure is the sum of the pressure of each individual gas:

$P_{total} = P_{1}+P_{2}+...$