Which of the following is an example of a measurement of velocity?

Ammonia enters the expansion valve of a refrigeration system at a pressure of 10 bar and a temperature of 22oC and exits at 2.0

KonstantinChe [14]

Answer:

The the quality of the refrigerant at the exit of the expansion valve is 0.179.

Explanation:

Given that,

Initial pressure = 10 bar

Temperature = 22°C

Final pressure = 2.0 bar

We using the value of h

$h = 293.4\ kJ/kg$

The refrigerant during expansion undergoes a throttling process

Therefore, $h_{1}=h_{2}$

We need to calculate the quality of the refrigerant at the exit of the expansion valve

At 2.0 bar,

The property of ammonia

$h_{f}=47.8 kJ/kg$

$h_{g}=1417.7 kJ/kg$

Using formula

$h_{2}=h_{f}+x(h_{g}-h_{f})$

Put the value into the formula

$293.4 =47.8+x(1417.7-47.8)$

$x=\dfrac{293.4-47.8}{1417.7-47.8}$

$x=0.179$

Hence, The the quality of the refrigerant at the exit of the expansion valve is 0.179.

6 0

3 years ago

What is the formula for Impedance for circuit with R, C, and L?

NikAS [45]

Answer:

The formula for Impedance for circuit with R, C, and L are:

$z=\sqrt{R^{2}+\left ( \omega L-\frac{1}{\omega C} \right )^2}$

The impedance Z of the series RLC circuit depend upon angular frequency ω. Impedance is measured in ohms and resistance (R), inductance reactance and capacitive reactance. Series RLC circuit consist of the resistance, a capacitance and an inductance connected in the circuits. Electrical impedance is the measurement of the opposition that a circuit present in a current.

3 0

2 years ago

Can someone please explain number 8?

guajiro [1.7K]

Answer: Ax=(Vx-Vox)/(T)

Vx=Vox+Ax*T

Solving for Ax in terms of Vx, Vox, T

Vx-Vox=Ax*t

Ax=(Vx-Vox)/(T)

This is saying the acceleration in the x-direction can be found by taking the difference between the finial and initial Velocity in x-direction and dividing it by the Total Time.

Any questions please feel free to ask. Thanks

8 0

2 years ago

The ceiling of your lecture hall is probably covered with acoustic tile, which has small holes separated by about 5.9 mm. Using

timurjin [86]

Answer:

45.88297 m

Violet

Explanation:

x = Gap between holes = 5.9 mm

$\lambda$ = Wavelength = 527 nm

D = Diameter of eye = 5 mm

L= Distance of observer from holes

From Rayleigh criteria we have the relation

$\frac{x}{L}=1.22\frac{\lambda}{D}\\\Rightarrow L=\frac{xD}{1.22\lambda}\\\Rightarrow L=\frac{5.9\times 10^{-3}\times 5\times 10^{-3}}{1.22\times 527\times 10^{-9}}\\\Rightarrow L=45.88297\ m$

A person could be 45.88297 m from the tile and still resolve the holes

Resolving them better means increasing the distance between the observer and the holes. It can be seen here that the distance is inversely proportional to the wavelength. Violet has a lower wavelength than red so, violet light would resolve the holes better.

5 0

3 years ago

The half-life of a certain radioactive substance is 12 hours. There are 19 grams present initially. a. Express the amount of su

neonofarm [45]

Answer:

(a) $N=19\times e^{-\lambda t}$