A pipe in a district heating network is transporting over-pressurized hot water (10 atm) at a mass flow of 0.5 kg/s. The pipe is

Answer:

B) P1 would have to increase to sustain the flow rate (correct)

C) Resistance would rise (correct)

Explanation:

Flow rate is measured at 10 liters per minute

Driving pressure (P1) stands at 20 cm H2O

Fixed downstream pressure (P2) is 5 cm H2O

The accurate statements when the lumen is pinched in the center of the tube are: P1 will increase to maintain the flow rate, and resistance will rise. This occurs because pinching the lumen decreases its diameter, leading to higher resistance, which is linearly related to pressure, thus P1 will also increase.

The incorrect statement is: the flow would decrease.

Answer:

The change in entropy of the steam is 2.673 kJ/K

Explanation:

The mass of the liquid-vapor mixture is 1.5 kg

The mass in the liquid phase is calculated as 3/4 × 1.5 kg = 1.125 kg

The mass in the vapor phase is calculated as 1.5 - 1.125 = 0.375 kg

According to the steam tables

At a pressure of 200 kPa (200/100 = 2 bar), the specific entropy of steam is found to be 7.127 kJ/kgK

The entropy of steam can be calculated as specific entropy multiplied by mass = 7.127 × 0.375 = 2.673 kJ/K

Answer:

The Python code is provided below with suitable comments

Explanation:

# convert list to set

male_names = set(['Oliver','Declan','Henry'])

# get name for removal and addition from user

remove_name = input("Enter remove name: ")

add_name = input("Enter add name: ")

# remove specified name from set

male_names.remove(remove_name)

# add new name to set

male_names.add(add_name)

# sort the resulting set

a = sorted(male_names)

# output the sorted set

print(a)