What are the factors that influence the power input to the compressor?

The correct answer is option (c) An experimental observation that the velocity of a fluid in contact with a solid surface is equal to the velocity of the surface.

Explanation

Solution:

When a fluid is in proximity to the boundary the solid and the velocities are the same or uniform for the fluid and the surface, no slip condition does not exist.

However, because the no-slip meets the expectations for gas and liquids, this condition no way connected in this case of two solid in proximity.

hence, the other options are wrong here.

6 0

3 years ago

A residential heat pump has a coefficient of performance of 1.49 How much heating effect, in kJ/h, will result when 4 kW is supp

AfilCa [17]

Answer:

21.456 kJ/h

Explanation:

See the figure attached. In this case

$W_{cycle} = 4 kW$

$Q_{out} = \text{heating effect}$

Coefficient of performance in heat pump is defined by

$COP = \frac{Q_{out}}{W_{cycle}}$

$Q_{out} =COP*W_{cycle}$

$Q_{out} =1.49*4 \, W$

$Q_{out} = 5.96 \, W$

Now it is necessary to change units, remember that Watt (W) is defined as J/s

$Q_{out} = 5.96 \frac{J}{s} \frac{3600s}{1 h} \frac{1 kJ}{1000 J}$

$Q_{out} = 21.456 \frac{kJ}{h}$

3 0

3 years ago

How much energy does it take to boil water for pasta? For a one-pound box of pasta

ArbitrLikvidat [17]

Answer:

a. 164 °F b. 91.11 °C c. 1439.54 kJ

Explanation:

a. [1 pts] How many degrees Fahrenheit (°F) must you raise the temperature?

Since the starting temperature is 48°F and the final temperature which water boils is 212°F, the number of degrees Fahrenheit we would need to raise the temperature is the difference between the final temperature and the initial temperature.

So, Δ°F = 212 °F - 48 °F = 164 °F

b. [2 pts] How many degrees Celsius (°C) must you raise the temperature?

To find the degree change in Celsius, we convert the initial and final temperature to Celsius.

°C = 5(°F - 32)/9

So, 48 °F in Celsius is

°C₁ = 5(48 - 32)/9

°C₁ = 5(16)/9

°C₁ = 80/9

°C₁ = 8.89 °C

Also, 212 °F in Celsius is

°C₂ = 5(212 - 32)/9

°C₂ = 5(180)/9

°C₂ = 5(20)

°C₂ = 100 °C

So, the number of degrees in Celsius you must raise the temperature is the temperature difference between the final and initial temperatures in Celsius.

So, Δ°C = °C₂ - °C₁ = 100 °C - 8.89 °C = 91.11 °C

c. [2 pts] How much energy is required to heat the four quarts of water from

48°F to 212°F (boiling)?

Since we require 15.8 kJ for every degree Celsius of temperature increase of the four quarts of water, that is 15.8 kJ/°C and it rises by 91.11 °C, then the amount of energy Q required is Q = amount of heat per temperature rise × temperature rise = 15.8 kJ/°C × 91.11 °C = 1439.54 kJ

8 0

3 years ago