8. The two-stroke engine must still complete all four stages of operation-it just does this in two piston strokes instead of

Air is heated from 50 F to 200 F in a rigid container with a heat transfer of 500 Btu. Assume that the air behaves as an ideal g

marissa [1.9K]

Answer:

$V=68.86ft^3$

Explanation:

$T_1$ =10°C, $T_2$ =93.33°C

Q=500 btu=527.58 KJ

$P_1= 2atm$

If we assume that air is ideal gas PV=mRT, ΔU= $mC_v(T_2-T_1)$

Actually this is closed system so work will be zero.

Now fro first law

Q=ΔU= $mC_v(T_2-T_1)$ +W

⇒Q= $mC_v(T_2-T_1)$

527.58 = $m\times 0.71(200-50)$

m=4.9kg

PV=mRT

$200V=4.9\times 0.287\times (10+273)$

$V=1.95m^3$ ( $V=1m^3=35.31ft^3$ )

$V=68.86ft^3$

6 0

4 years ago

A _____ satellite system employs many satellites that are spaced so that, from any point on the Earth at any time, at least one

Wittaler [7]

Answer:

d. low earth orbit (LEO)

Explanation:

This type of satellites form a constellation deployed as a series of “necklaces” in such a way that at any time, at least one satellite is visible by a receiver antenna, compensating the movement due to the earth rotation.

Opposite to that, a geostationary satellite is at an altitude that makes it like a fixed point over the Earth´s equator, rotating synchronously with the Earth, so it is always visible in a given area.

3 0

3 years ago

Write a static method called quadrant that takes as parameters a pair of real numbers representing an (x, y) point and that retu

svetlana [45]

Full Question

Write a static method called quadrant that takes as parameters a pair of real numbers representing an (x, y) point and that returns the quadrant number for that point.

Recall that quadrants are numbered as integers from 1 to 4 with the upper-right quadrant numbered 1 and the subsequent quadrants numbered in a counter-clockwise fashion. Notice that the quadrant is determined by whether the x and y coordinates are positive or negative numbers. If a point falls on the x-axis or the y-axis, then the method should return 0.

Answer

public int quadrant(double x, double y) // Line 1

{

if(x > 0 && y > 0){ //Line 2

return 1;

}

if(x < 0 && y > 0){ // Line 3

return 2;

}

if(x < 0 && y < 0) {// Line 4

return 3;

}

if(x > 0 && y < 0) {// Line 5

return 4;

}

return 0;

}

Explanation:

Line 1 defines the static method.

The method is named quadrant and its of type integer.

Along with the method definition, two variables x and y of type double are also declared

Line 2 checks if x and y are greater than 0.

If yes then the program returns 1

Line 3 checks if x is less than 0 and y is greater than 0

If yes then the program returns 2

Line 4 checks if x and y are less than 0

If yes then the program returns 3

Line 5 checks is x is greater than 0 and y is less than 0

If yes then the program returns 4

7 0

4 years ago

A rectangular block of material with shear modulus G= 620 MPa is fixed to rigid plates at its top and bottom surfaces. Thelower

PIT_PIT [208]

Answer:

γ $_{xy}$ =0.01, P=248 kN

Explanation:

Given Data:

displacement = 2mm ;

height = 200mm ;

l = 400mm ;

w = 100 ;

G = 620 MPa = 620 N//mm²; 1MPa = 1N//mm²

a. Average Shear Strain:

The average shear strain can be determined by dividing the total displacement of plate by height

γ $_{xy}$ = displacement / total height

= 2/200 = 0.01

b. Force P on upper plate:

Now, as we know that force per unit area equals to stress

τ = P/A

Also, τ = Gγ $_{xy}$

By comapring both equations, we get

P/A = Gγ $_{xy}$ ------------ eq(1)

First we need to calculate total area,

A = l*w = 400 * 100= 4*10^4mm²

By putting the values in equation 1, we get

P/40000 = 620 * 0.01

P = 248000 N or 2.48 *10^5 N or 248 kN

6 0

3 years ago

A particle travels along a straight line with a velocity v = (12 – 3t2) m/s. When t = 1 s, the particle is located 10 m to the l

arlik [135]

Answer:

The displacement from t = 0 to t = 10 s, is -880 m

Distance is 912 m

Explanation:

$v = (12 - 3t^2) m/s = ds/dt$ . . . . . . . . . . A

integrate above equation we get

$s = 12t - t^3 + C$

from information given in the question we have

t = 1 s, s = -10 m

so distance s will be

-10 = 12 - 1 + C,

C = -21

$s(t) = 12t - t^3 - 21$

we know that acceleration is given as

$a(t) = dv/dt = -6t$

[FROM EQUATION A]

Acceleration at t = 4 s, a(4) = -24 m/s^2

for the displacement from t = 0 to t = 10 s,

$s(10) - s(0) = (12*10 - 10^3 - 21) - (-21) = -880 m$

the distance the particle travels during this time period:

let v = 0,

$3t^2 = 12$

t = 2 s

Distance $= [s(2) - s(0)] + [s(2) - s(10)] = [1\times 2 - 2^3] + [(12\times 2 - 2^3) - (12\times 10 - 10^3)] = 912 m$

7 0

4 years ago