PLSSSSS Help !!!!!!!!!!!. It's due today. <br> I will give brainliest to correct answer

A generator is to be driven by a small Pelton wheel with a head of 91.5m at inlet to the nozzle and discharge of 0.04m^3/s. The

maria [59]

Answer:

ratio = 412

speed of wheel = 13.63

Explanation:

given data

head h = 91.5 m

discharge Q = 0.04 m³/s

wheel rotates N = 720 rpm

velocity coefficient Cv = 0.98

efficiency of the wheel η = 80 %

ratio of bucket speed to jet speed $\frac{u}{v}$ = 0.46

to find out

wheel to jet diameter ratio and power specific speed of the wheel

solution

we know that discharge = area × velocity .............1

here velocity = Cv√(2gh)

velocity = 0.98√(2×9.81×91.5) = 41.52 m/s

and area = $\frac{\pi }{4} d^2$

so from equation 1

0.04 = $\frac{\pi }{4} d^2$ × 41.52

d = 0.00123 m = 1.23 mm

we know bucket speed to jet speed = 0.46

so bucket speed u = 0.46 v

bucket speed u = 0.46 × 41.52 = 19.1 m/s

and bucket speed = $\frac{\pi D N}{60}$

so 19.1 = $\frac{\pi D 720}{60}$

so D = 0.506 m = 506.62 mm

so ratio is $\frac{D}{d} = \frac{506.62}{1.23}$

ratio = 412

and

we know efficiency = $\frac{outputpower}{inputpower}$

0.80 × ρQgh = output power

power output = 0.80 ×1000×0.04×9.81×91.5

power output P = 28.72 kW

so

speed of wheel is

speed of wheel = $\frac{N\sqrt{P} }{h^{5/4}}$

speed of wheel = $\frac{720\sqrt{28.72} }{91.5^{5/4}}$

speed of wheel = 13.63

7 0

4 years ago

Oliver is designing a new children's slide to increase speed at which a child can descend.His first design involved steel becaus

goldenfox [79]

Answer:

Steel can rusts easily in the presence of moisture and oxygen, and tarnishes as the rust progresses.

Explanation:

Steel is an alloy of carbon and iron. it is a very useful alloy that is found in almost any engineered piece. The problem with steel is that it is very susceptible to rust, and the cost of maintaining it in order to prevent rust is very high. Steel rusts in the presence of moisture and oxygen (rust is an oxidation-reduction process). Using it as a water slide exposes it constantly to moisture, and to prevent it from rusting in this case will involve a lot of maintenance cost, which is why steel is not advisable to be used in this case.

7 0

4 years ago

A cylindrical specimen of a brass alloy having a length of 60 mm (2.36 in.) must elongate only 10.8 mm (0.425 in.) when a tensil

Gemiola [76]

The radius of the specimen is 60 mm

<u>Explanation:</u>

Given-

Length, L = 60 mm

Elongated length, l = 10.8 mm

Load, F = 50,000 N

radius, r = ?

We are supposed to calculate the radius of a cylindrical brass specimen in order to produce an elongation of 10.8 mm when a load of 50,000 N is applied. It is necessary to compute the strain corresponding to this

elongation using Equation:

ε = Δl / l₀

ε = 10.8 / 60

ε = 0.18

We know,

σ = F / A

Where A = πr²

According to the stress-strain curve of brass alloy,

σ = 440 MPa

Thus,

$sigma = 50,000 / \pi (r)^2\\\\440 X 10^6 = \frac{50,000}{3.14 X (r)^2}\\\\r = 0.06m\\r = 60mm\\\\\\$

Therefore, the radius of the specimen is 60 mm

3 0

4 years ago

Question #4

mihalych1998 [28]

Answer:

C. they need on the job experience I think

7 0

3 years ago

# line 1 age = int(input("Enter your age: ")) # line 3 print("Invalid input") If we want the computer to display "Invalid input"

user100 [1]

Answer:

Insert

'try:' at line 1

'except:' at line 3

Explanation:

The "try and except" commands in Python are used for exception handling.

try: the statements under this block are executed normally

except: the the statements under this block are executed when there is an exception.

We can use these commands to handle errors, for example, in the given scenario we don't want the user to enter a floating point number such as

1.5, 2.6 etc.

When the user enters an integer number then the except command is not executed.

When the user enters a floating point number then the except command is executed, program is stopped and error message is shown that is at line 4

Python code:

# line 1

try:

# line 2

age = int(input("Enter your age: "))

# line 3

except:

# line 4

print("Invalid input")

Output:

Test 1:

Enter your age: 20

Test 2:

Enter your age: 20.5

Invalid input

5 0

3 years ago

PLSSSSS Help !!!!!!!!!!!. It's due today. I will give brainliest to correct answer