Sinks must be used for the correct intended purpose to prevent

The vertical and horizontal poles at the traffic-light assembly are erected first. Determine the additional force and moment rea

konstantin123 [22]

Answer:

1. Az=258 lb

2. My=3440 ft lb

3. ∑Mz= 0

Explanation:

∑ Fx= Ax=0

∑ Fy= Ay=0

∑ Fz= Az-86-86-86

Az=258 lb

∑Mx=86 X 31 +Mx=0

Mx=2666 ft lb

∑My=86 X 40 +My=0

My=3440 ft lb

∑Mz= 0

6 0

3 years ago

A gas expands in a piston-cylinder assembly from p1 = 8 bar, V1 = 0.02 m3 to p2 = 2 bar. The relation between pressure and volum

Charra [1.4K]

Answer:

The heat transfer is 29.75 kJ

Explanation:

The process is a polytropic expansion process

General polytropic expansion process is given by PV^n = constant

Comparing PV^n = constant with PV^1.2 = constant

n = 1.2

(V2/V1)^n = P1/P2

(V2/0.02)^1.2 = 8/2

V2/0.02 = 4^(1/1.2)

V2 = 0.02 × 3.2 = 0.064 m^3

W = (P2V2 - P1V1)/1-n

P1 = 8 bar = 8×100 = 800 kPa

P2 = 2 bar = 2×100 = 200 kPa

V1 = 0.02 m^3

V2 = 0.064 m^3

1 - n = 1 - 1.2 = -0.2

W = (200×0.064 - 800×0.02)/-0.2 = -3.2/-0.2 = 16 kJ

∆U = 55 kJ/kg × 0.25 kg = 13.75 kJ

Heat transfer (Q) = ∆U + W = 13.75 + 16 = 29.75 kJ

7 0

3 years ago

why are apartments called apartments if there together? and why are buildings called buildings if there already built? hmmmm

kumpel [21]

Answer:huh

U right Even though all the apartments within a single building are indeed stuck together, they are also apart from each other.

For you’re second question That means when the building was not built, at that time it was building, now when it is built we remember the past and give it respect of being built - so a building is called a building when it is already built - well it was building back at that time when it was not built !!!

Explanation:

8 0

3 years ago

An inventor claims to have developed a food freezer that at steady state requires a power input of 0.25 kW to extract energy by

Serga [27]

Answer:

investor claim is acceptable

Explanation:

given data

Win = 0.25 kW

Qc = 3000 J/s = 3kW

Th = 293 K

Tc = 270 K

solution

we get here coefficient of performance of cycle is

coefficient of performance = $\frac{Qc}{Win}$ ..................1

put here value and we get

coefficient of performance = $\frac{3}{0.25}$

coefficient of performance = 1.2

and

coefficient of performance of ideal refrigeration is

coefficient of performance = $\frac{Tc}{Th-Tc}$ ..................2

coefficient of performance = $\frac{270}{293-270}$

coefficient of performance = 11.74

and

we can see here that coefficient of performance of ideal refrigeration is is more than real cycle coefficient of performance

so investor claim is acceptable

6 0

2 years ago

Define the following terms: data, database, DBMS, database system, database catalog, program-data independence, user view, DBA,

nalin [4]

Answer:

data - Any form of value in a column of a table in a relational database.

DBMS - Short for Database management system, which is a software that can be used to create, manipulate and view databases, e.g. MS SQL Server.

database system - Same as DBMS.

database catalog - Place where the metadata of a Database including its tables, users etc. exists, e.g. date created, size, number of columns etc. Also known as Data Dictionary.

program-data independence - Program-data independence refers to the design of keeping different levels of database (external, logical and physical) separate and loosely coupled from each other, for easier maintenance or modification work.

DBA - Short for Database Administrator, person responsible for maintaining the database. Its main responsibility is to keep the data clean and safe i.e. data doesn't contain wrong or invalid data, and is safe from viruses and is backed up.

end user - Anyone who is not directly interacting with a database, but through some software, like website or mobile application.

persistent object - An object of a class in a program, that interacts with the underlying database and is responsible for manipulating the database, the program is connected to.

transaction-processing system - A transaction process system is part of a software, responsible for making sure critical business transactions, like crediting or debiting money, either goes through cleanly or doesn't at all.

6 0

3 years ago