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1 year ago

Two kilograms of air in a piston-cylinder assembly undergoes an isothermal

Engineering

1 answer:

Lubov Fominskaja [6]1 year ago

7 0

Answer:

a) 0.39795 kJ/K

b) 79.589.37 kJ

Explanation:

m = Mass of air = 2 kg

Temperature = 200 K

P₁ = Initial pressure = 300 kPa

P₂ = Final pressure = 600 kPa

R = mass-specific gas constant for air = 287.058 J/kgK

a) For isentropic process

∴ Entropy is generated in the process is 0.39795 kJ/K

∴ Amount of lost work is 79.589.37 kJ

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A metal bar has a 0.6 in. x 0.6 in. cross section and a gauge length of 2 in. The bar is loaded with a tensile force of 50,000 l

Aleks [24]

Answer:

modulus =3.97X10^6 Ib/in^2, Poisson's ratio = 0.048

Explanation:

Modulus is the ratio of tensile stress to tensile strain

Poisson's ratio is the ratio of transverse contraction strain to longitudinal extension strain within the direction of the stretching force

And contraction occur from 0.6 in x 0.6 in to 0.599 in x 0.599 in while 2 in extended to 2.007, with extension of 0.007 in

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2 years ago

True or false. Part of the mission of the NTSB is to determine the probable cause of an accident

eimsori [14]

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2 years ago

The fracture toughness of a stainless steel is 137 MPa*m12. What is the tensile impact load sustainable before fracture that a r

Charra [1.4K]

Answer:

7.7 kN

Explanation:

The capacity of a material having a crack to withstand fracture is referred to as fracture toughness.

It can be expressed by using the formula:

$K = \sigma Y \sqrt{\pi a}$

where;

fracture toughness K = 137 MPa $m^{1/2}$

geometry factor Y = 1

applied stress $\sigma$ = ???

crack length a = 2mm = 0.002

∴

$137 =\sigma \times 1 \sqrt{ \pi \times 0.002 }$

$137 =\sigma \times 0.07926$

$\dfrac{137}{0.07926} =\sigma$

$\sigma = 1728.489 MPa$

Now, the tensile impact obtained is:

$\sigma = \dfrac{P}{A}$

P = A × σ

P = 1728.289 × 4.5

P = 7777.30 N

P = 7.7 kN

7 0

2 years ago

2. The moist weight of 0.1 ft3 of soil is 12.2 lb. If the moisture content is 12% and the specific gravity of soil solids is 2.7

adell [148]

The answers to dry unit weight, void ratio, porosity, degree of saturation, volume occupied by water are respectively;

γ_d = 108.93 lb/ft³; e = 0.56; n = 0.36; S = 0.58; V_w = 0.021 ft³

<h3>Calculation of Volume and Weight of soil</h3>

We are given;

Moist weight; W = 12.2 lb

Volume of moist soil; V = 0.1 ft³

moisture content; w = 12% = 0.12

Specific gravity of soil solids; G_s = 2.72

A) Formula for dry unit weight is;

γ_d = γ/(1 + w)

where γ_w is moist unit weight as;

γ_w = W/V

γ_w = 122/0.1 = 122 lb/ft³

Thus;

γ_d = 122/(1 + 0.12)

γ_d = 108.93 lb/ft³

B) Formula for void ratio is;

e = [(G_s * γ_w)/γ_d] - 1

e = [(2.72 * 122)/108.93] - 1

e = 0.56

C) Formula for porosity is;

n = e/(1 + e)

n = 0.56/(1 + 0.56)

n = 0.36

D) Formula for degree of saturation is;

S = (w * G_s)/e

S = (0.12 * 2.72)/0.56

S = 0.58

E) Volume occupied by water is gotten from;

V_w = S*V_v

where;

V_v is volume of voids = nV

V_v = 0.36*0.1

V_v = 0.036 ft³

Thus;

V_w = 0.58 * 0.036

V_w = 0.021 ft³

Read more about Specific Gravity of Soil at; brainly.com/question/14932758

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2 years ago

In several sentences, please discuss:

Bezzdna [24]

Answer:

Everything is explained below in the Explanation section.

Explanation:

<em>a) TMDL stands for = Total Daily Maximum Loads</em>

TMDL is the measure of total maximum amount of pollutant allowed in the water body. TMDL is a important tool to maintain the quality of water and measure the aquatic pollution.

Whereas, the formula to calculate TMDL is as follows:

TMDL = Sum of waste load allocations (point source) + Sum of load allocations (non point sources and background) + Margin of Safety

<em>b) Dead Zones :</em>

Dead zones are zones which are termed as hypoxic which are low in oxygen because of the extreme aquatic pollution caused by human activities which in result deplete the oxygen level above the and below the oceans most required by the marine life. In addition, dead zones are those areas where oxygen is low and life in danger is high comparatively to other areas of oceans.

The main cause of that dead zones is because of eutrophication which means adding dangerous chemical nutrients in the water in exceeding amounts.

<em>c) Why Ammonia-nitrogen is detrimental to waterbodies: </em>

1. Ammonia nitrogen is a very toxic pollutant often found in landfills and sewage and waste products.

2. Ammonia nitrogen reduces the ability of water to disinfect its inhabitants and it reduces the purity. Furthermore, it changes the smell of the water and pollutes it.

3. Last but not the least, if you increase the concentration of ammonia nitrogen, the dissolved oxygen rate will be decreased and it has a inverse relation which is very dangerous to marine life underwater.

<em>d) Streeter-Phelps DO curve:</em>

Please refer to the attachment, I have attached the curve.

This curve is used to evaluate the dissolved oxygen in the water with varying distance.

It can be further studied from the curve that, how much loss sewage and other pollutants can endure upon the marine life.

8 0

2 years ago