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2 years ago

What is the correct statement regarding the stress over the section of a shaft in torsion?

Engineering

1 answer:

4vir4ik [10]2 years ago

7 0

Answer:

d) A shear stress that varies linearly over the section.

Explanation:

Given that shaft is under pure torsion

As we know that relationship between shear stress in the shaft and radius given as

$\dfrac{T}{J}=\dfrac{\tau}{r}$

For solid shaft

$J=\dfrac{\pi}{64}d^4$

Therefore shear stress given as

$\tau=\dfrac{T}{J}\times r$

T=Applied torque on the shaft

τ=Shear stress at any radius r

From the above equation we can say that shear stress is vaying linearly with the radius of the shaft

Therefore the answer will be d.

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(TCO 1) Name one disadvantage of fixed-configuration switches over modular switches. a. Ease of management b. Port security b. F

frutty [35]

Answer:

The answer is A.

Explanation:

Two main types of network switches, modular and fixed configuration switches, are used for connecting the devices with one another provided they are on the same network.

As the name suggests, modular switches can be configured according to your needs and specific situations where you need a different setup.

The one advantage fixed-configuration switches have over the modular switches is that they are easier to operate. You can't change anything for a different application but they are simpler to setup and use, you can just plug them in and start using. They are usually for the more casual end-user and home networks etc.

I hope this answer helps.

5 0

3 years ago

A sample of wastewater is diluted 10 times. The diluted solution has an ultimate biochemical oxygen demand (BOD), Lo, of 30 mg/L

zzz [600]

Answer:

474.59 mg/L

Explanation:

Given that

BOD = 30 mg/L

Original BOD = 30 mg/L × dilution factor

Original BOD = 30 mg/L × 10 = 300 mg/L

$L_o = \frac{BOD}{1-e^{-5t}}$

here $L_o$ is the ultimate BOD ; BOD is the biochemical oxygen demand ; t = 0.20 /day

$L_o = \frac{300}{1-e^{-5(0.20)}}$

$L_o = 474.59 \ mg/L$

3 0

3 years ago

Which of the following conditions were present in over 80% of paddling fatalities from 1995-2000?

Minchanka [31]

Answer:

80% of the people that were killed weren't wearing a safety flotation device ( in correct terminology Personal Flotation Device, or PFD )

Explanation:

Hence they drowned due to the lack of safety.

3 0

3 years ago

Give me some examples of fragile structures.

Anvisha [2.4K]

Answer:

i don't know if this help tell me if i am wrong

Explanation:

Gravity is the force that pulls all elements of matter together. Matter refers to things you can physically touch. The more matter there is, the greater the amount of gravity or force. This means that the Earth or other planets have a great deal of pull and that everything on Earth is pulled back to Earth.

Some examples of the force of gravity include:

The force that holds the gases in the sun.

The force that causes a ball you throw in the air to come down again.

The force that causes a car to coast downhill even when you aren't stepping on the gas.

The force that causes a glass you drop to fall to the floor.

3 0

3 years ago

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

2 years ago