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3 years ago

Cavitation in pump assemblies can be avoided by decreasing tank pressure. a)-True b)-False

Engineering

1 answer:

IgorLugansk [536]3 years ago

7 0

Answer:

a) True

Explanation:

Cavitation in a pump occurs when the pressure of the liquid inside the pump suction is less than the vapour pressure at the suction. And also when the pump discharge pressure is extremely high.

Therefore cavitation in the pump assemblies can be avoided by decreasing the tank pressure because discharge cavitation takes place when the pressure at the pump discharge is extremely high. High pressure at the discharge end of the pump prevents the water from flowing easily out, thereby recirculating the water within the pump which causes cavitation. So when the tank pressure is low, the pump discharge pressure will be low thus avoiding cavitation.

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An aircraft component is fabricated from an aluminum alloy that has a plane strain fracture toughness of 40 . For an applied str

erma4kov [3.2K]

Answer:

B. 2.3mm

Explanation:

The correct answer for the given question is B. 2.3mm. Some aircraft are made are fabricated from aluminium which has plane stain fracture toughness. In the given scenario the plane stain toughness is

Ktc = 40 [ MPa $\sqrt{(m)}$ ]

When the Ktc increases the fracture will appear on the aircraft. In this case the maximum crack until the fracture failure is 2.5mm.

8 0

3 years ago

Let m be an integer in the set {0,1,2,3,4,5,6,7,8, 9}, and consider the following problem: determine m by asking 3-way questions

kupik [55]

Answer:

Take any algorithm if that algorithm solves this problem it can be represented as a ternary decision tree. Therefore each question has at most three answers.

There are ten possible verdicts, the height of such kind of tree should satisfy

ℎ >= ⌈log3(10)⌉ = 3

Hence no such algorithm can ask less than three questions in the worst case.

---

Each and every internal node represents a question asking whether m belongs to one of three possible subset of {0, 1, 2, 3, 4, 5, 6, 7, 8, 9} or not

For example 0123|456|789 represented the questionDoes “m: belongs to {0, 1, 2, 3}, to {4, 5, 6}, or to {7, 8, 9}?"

Verdicts are placed in brackets "[ ]"

Explanation:

decision tree is attached below

5 0

3 years ago

The high-pressure air system at OSU's Aerospace Research Center is fed by a set of two cylindrical tanks. Each tank has an outer

lana66690 [7]

Answer:

179000 lb

Explanation:

The supports must be able to hold the weight of the tank and the contents. Since tanks are pressure tested with water, and the supports cannot fail during testing, we disregard the air and will consider the weight of water.

The specific weight of water is ρw = 62.4 lbf/ft^3

These tanks are thin walled because

D / t = 4.6 / 0.1 = 46 > 10

To calculate the volume of steel we can approximate it by multiplying the total surface area by the thickness:

A = 2 * π/4 * D^2 + π * D * h

The steel volume is:

V = A * t

The specific weight is

ρ = δ * g

ρs = 499 lbm/ft^3 * 1 lbf/lbm = 499 lbf/ft^3

The weight of the steel tank is:

Ws = ρs * V

Ws = ρs * A * t

Ws = ρs * (2 * π/4 * D^2 + π * D * h) * t

Ws = 499 * (π/2 * 4.6^2 + π * 4.6 * 50) * 0.1 = 37700 lb

The weight of water can be approximated with the volume of the tank:

Vw = π/4 * D^2 * h

Ww = ρw * π/4 * D^2 * h

Ww = 62.4 * π/4 * 4.6^2 * 50 = 51800 lb

Wt = Ws + Ww = 37700 + 51800 = 89500 lb

Assuming the support holds both tanks

2 * 89500 = 179000 lb

The support must be able to carry 179000 lb

3 0

4 years ago

A motorist is driving his car at 60km/hr when he observes that a traffic light 250m ahead turns red. The traffic light is

Alecsey [184]

Explanation:

Okay soo-

Given-

u = 60 km/hr = 60×1000/3600=50/3 m/s

t = 20 s

s = 250 m

a = ?

v = ?

Solution -

Here, acceleration is uniform.

(a) According to 2nd kinematics equation,

s = ut + ½at^2

250 = 50/3 ×20 + 0.5×a×20×20

250-1000/3=200a

(750-1000)/3=200a

a = -250/(3×200)

a = -5/12

a = 0.4167 m/s^2

The required uniform acceleration of the car is 0.4167 m/s^2.

(b) According to 1st kinematics equation

v = u + at

v = 50/3 + (-5/12)×20

v = 50/3-25/3

v = 25/3

v = 8.33 m/s

The speed of the car as it passes the traffic light is 8.33 m/s.

Good luck!

5 0

3 years ago

The rainfall rate in a certain city is 20 inches per year over an infiltration area that covers 33000 acres. Twenty percent of t

Mariana [72]

Answer:

The rate at which water is being withdrawn from the river by the city is 57353 acre-ft/y

Explanation:

Please look at the solution in the attached Word file

Download docx

3 0

4 years ago