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3 years ago

What does it mean to test a hypothesis?

Engineering

1 answer:

AysviL [449]3 years ago

6 0

Answer: See if the results of an experiment are what the scientist predicted.

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What are the main subsystem of GSM<br> network

Paraphin [41]

Explanation:

Network and Switching Subsystem (NSS)

Base-Station Subsystem (BSS)

Mobile station (MS)

Operation and Support Subsystem (OSS)

6 0

3 years ago

A Carnot heat engine operates between 1000 deg F and 50 deg F, producing 120 BTU of work. What is the heat input to the engine?

Mazyrski [523]

Answer:

184.6 BTU

Explanation:

The thermal efficiency for a Carnot cycle follows this equation:

η = 1 - T2/T1

Where

η: thermal efficiency

T1: temperature of the heat source

T2: temperature of the heat sink

These temperatures must be in absolute scale:

1000 F = 1460 R

50 F = 510 R

Then

η = 1 - 510/1460 = 0.65

We also know that for any heat engine:

η = L / Q1

Where

L: useful work

Q1: heat taken from the source

Rearranging:

Q1 = L / η

Q1 = 120 / 0.65 = 184.6 BTU

4 0

4 years ago

Why the velocity potential Φ(x,y,z,t) exists only for irrotational flow

Black_prince [1.1K]

Answer:

$\omega_y,\omega_x,\omega_Z$ all are zero.

Explanation:

We know that if flow is possible then it will satisfy the below equation

$\dfrac{\partial u}{\partial x}+\dfrac{\partial v}{\partial y}+\dfrac{\partial w}{\partial z}=0$

Where u is the velocity of flow in the x-direction ,v is the velocity of flow in the y-direction and w is the velocity of flow in z-direction.

And velocity potential function $\phi$ given as follows

$u=-\frac{\partial \phi }{\partial x},v=-\frac{\partial \phi }{\partial y},w=-\frac{\partial \phi }{\partial z}$

Rotationality of fluid is given by $\omega$

$\frac{\partial v}{\partial x}-\frac{\partial u}{\partial y}=\omega_Z$

$\frac{\partial v}{\partial z}-\frac{\partial w}{\partial y}=\omega_x$

$\frac{\partial w}{\partial x}-\frac{\partial u}{\partial z}=\omega_y$

So now putting value in the above equations ,we will find

$\omega =\frac{\partial \phi }{\partial x},u=\frac{\partial \phi }{\partial x},$

$\omega_y=\dfrac{\partial^2 \phi }{\partial z\partial x}-\dfrac{\partial^2 \phi }{\partial z\partial x}$

So $\omega_y$ =0

Like this all $\omega_y,\omega_x,\omega_Z$ all are zero.

That is why velocity potential flow is irroational flow.

5 0

4 years ago

A 12-ft high retaining wall has backfill of granular soil with an internal angle of friction of 30 and unit weight of 125 pef. W

irakobra [83]

Answer:

P_p = 27000 psf

Explanation:

given,

height of the retaining wall = h = 12 ft

internal angle of friction (∅)= 30°

unit weight = 125 pcf

Rankine passive earth pressure = ?

k_p is the coefficient of passive earth pressure

$k_p = \dfrac{1 + sin\phi}{1 - sin\phi}$

$k_p = \dfrac{1 + sin30^0}{1 - sin30^0}$

k_p = 3

Passive earth pressure

$P_p = \dfrac{1}{2}k_p \gamma H^2$

$P_p = \dfrac{1}{2}\times 3\times 125 \times 12^2$

P_p = 27000 psf

Rankine passive earth pressure on the wall is equal to P_p = 27000 psf

7 0

3 years ago

If I were to build a fully functional robotic leg what type of circuit board should I use?

garik1379 [7]

Answer:

A good one

Explanation:

Rotatianal degrees and stuf for different types of movement would take some proccesing power and if it were linked to brain neurons you would need one not prone to frying

5 0

3 years ago