When watching your weight, you want to snack smart. To do that, you want a snack that is going to _________

At a certain location, wind is blowing steadily at 5 mph. Suppose that the mass density of air is 0.0796 lbm/ft3 and determine t

nlexa [21]

Answer:

The radius of a wind turbine is 691.1 ft

The power generation potential (PGP) scales with speed at the rate of 7.73 kW.s/m

Explanation:

Given;

power generation potential (PGP) = 1000 kW

Wind speed = 5 mph = 2.2352 m/s

Density of air = 0.0796 lbm/ft³ = 1.275 kg/m³

Radius of the wind turbine r = ?

Wind energy per unit mass of air, e = E/m = 0.5 v² = (0.5)(2.2352)²

Wind energy per unit mass of air = 2.517 J/kg

PGP = mass flow rate * energy per unit mass

PGP = ρ*A*V*e

$PGP = \rho *\frac{\pi r^2}{2} *V*e \\\\r^2 = \frac{2*PGP}{\rho*\pi *V*e} , r=\sqrt{ \frac{2*PGP}{\rho*\pi *V*e}} = \sqrt{ \frac{2*10^6}{1.275*\pi *2.235*2.517}}$

r = 210.64 m = 691.1 ft

Thus, the radius of a wind turbine is 691.1 ft

PGP = CVᵃ

For best design of wind turbine Betz limit (c) is taken between (0.35 - 0.45)

Let C = 0.4

PGP = Cvᵃ

take log of both sides

ln(PGP) = a*ln(CV)

a = ln(PGP)/ln(CV)

a = ln(1000)/ln(0.4 *2.2352) = 7.73

The power generation potential (PGP) scales with speed at the rate of 7.73 kW.s/m

5 0

3 years ago

Consider the following relational database that Best Airlines uses to keep track of its mechanics, their skills, and their airpo

Musya8 [376]

Answer:

Explanation:

A)

SELECT MECHNAME,AGE FROM MECHANIC;

B)

SELECT AIRNAME,SIZE FROM AIRPORT WHERE SIZE>=20 AND STATE='CALIFORNIA' AND YEAROPENED >=1935 ORDER BY SIZE ASC;

C)

SELECT AIRNAME,SIZE FROM AIRPORT WHERE (SIZE>=20 OR YEAROPENED >=1935) AND STATE='CALIFORNIA';

D)

SELECT AVG(SIZE) FROM AIRPORT WHERE STATE='CALIFORNIA' AND YEAROPENED >=1935;

E)

SELECT COUNT(AIRNAME) FROM AIRPORT WHERE STATE='CALIFORNIA' AND YEAROPENED >=1935;

F)

SELECT COUNT(AIRNAME),STATE FROM AIRPORT WHERE YEAROPENED>=1935 GROUP BY STATE;

G)

SELECT COUNT(AIRNAME),STATE FROM AIRPORT WHERE YEAR OPENED>=1935 GROUP BY STATE HAVING COUNT(*)>=5;

H)

SELECT MECHNAME FROM MECHANIC A JOIN AIRPORT B

ON A.AIRNAME=B.AIRNAME AND B.STATE='CALIFORNIA';

I)

SELECT MECHNAME FROM MECHANIC A

JOIN QUALIFICATION B

ON A.MECHNUM=B.MECHNUM

AND B.PROFRATE=4

JOIN SKILL C

ON B.SKILLNUM=C.SKILLNUM

AND SKILLNAME='FAN BLADE RELACEMENT';

J) SELECT MECHNAME FROM MECHANIC A

JOIN QUALIFICATION B

ON A.MECHNUM=B.MECHNUM

AND B.PROFRATE=4

JOIN SKILL C

ON B.SKILLNUM=C.SKILLNUM

AND SKILL NAME='FAN BLADE REPLACEMENT'

JOIN AIRPORT D

ON A.AIRNAME=D.AIRNAME

AND STATE='CALIFORNIA';

K) SELECT SUM(SALARY),CITY FROM MECHANIC A

JOIN AIRPORT B

ON A.AIRNAME=B.AIRNAME

AND STATE='CALIFORNIA'

GROUP BY CITY;

L) SELECT MAX(SIZE) FROM AIRPORT ;

M) SELECT MAX(SIZE) FROM AIRPORT WHERE STATE='CALIFORNIA';

6 0

3 years ago

Isn't this website cheating?

Orlov [11]

Answer: What website?

Explanation:

8 0

3 years ago

Read 2 more answers

Write 3 classes with three levels of hierarchy: Base, Derive (child of base), and D1 (child of Derive class). Within each class,

PIT_PIT [208]

Answer:

class Base

{

void m1()

{

System.out.println("Origin: Base Class");

}

class Derive extends Base

{

void m1()

{

System.out.println("Origin: Derived Class");

}

class D1 extends Derive

{

void m1()

{

System.out.println("Origin: D1 - Child of Derive Class");

}

class TestDynamicBinding

{

public static void main(String args[])

{

Base base = new Base(); // object of Base class

Derive derive = new Derive(); // object of Derive class

D1 d1 = new D1(); // object of D1 class

Base reference; // Reference of type Base

reference = base; // reference referring to the object of Base class

reference.m1(); //call made to Base Class m1 method

reference = derive; // reference referring to the object of Derive class

reference.m1(); //call made to Derive Class m1 method

reference = d1; // reference referring to the object of D1 class

reference.m1(); //call made to D1 Class m1 method

}

Explanation:

The solution demonstrates dynamic binding behavior because the linking procedure used calls overwritten method m1() is made at run time rather than doing it at the compile time. The code to be executed for this specific procedural call is also known at run time only.

6 0

3 years ago

You are developing a mind map for measuring the viscosity of fluid. At which stage in the process will you specify the equipment

kipiarov [429]

Answer:

Defining the subtopics

6 0

3 years ago

When watching your weight, you want to snack smart. To do that, you want a snack that is going to __________.