Thermodynamics Midterm Exam Part 2

BSU Lipa students constructed a system to supply water to a mountainside village located 180 m above sea level from a spring in the valley below at 20 m below sea level. When the pipe from the spring to the village is full of water, but no water is flowing, what is the pressure difference between the end of the pipe at the spring and the end of the pipe in the village?

• 19.62 bar

• 15.696 bar

• 196.2 bar

• 156.96

Determine the pressure at points B in the figure shown if the density of CCl4 is 1,590.0 kg/m3 and that of water is 1000.0 kg/m3.

• 109,279.929 Pa

• 190,279.929 Pa

• 169,317.1290 Pa

• 129,792.812 Pa

Determine the pressure at points A in the figure shown if the density of CCl4 is 1,590.0 kg/m3 and that of water is 1000.0 kg/m3.

• 109,279.929 Pa

• 97,409.8290 Pa

• 79,317.1290 Pa

• 129,792.812 Pa

A tank contains a mixture of 10 kg of nitrogen and 50 kg of carbon monoxide. The total tank volume is 40m3. Determine the specific volume of the mixture.

• 0.5 m3/kg

• 2 m3/kg

• 0.6 m3/kg

• 1.5m3/kg

A hiker is carrying a barometer that measures 101.3 kPa at the base of the mountain. The barometer reads 60.0 kPa at the top of the mountain. The average air density is 1.27 kg/m3• Determine the height of the mountain.

• 1.7332 km

• 3.3150 km

• 3,315.0 km

• 1733.2 km

If the velocity of a fluid is increased to twice its original value, what will happen to pressure drop?

• it will be 2x the original pressure drop

• it will be 4x the original pressure drop

• it will be halved the original pressure drop

• nothing will happen

A centrifugal pump compresses 2300 liters/min of water from 98 kPa to 300 kPa. The inlet and outlet temperatures are 25°C. The inlet and discharge piping are on the same level, but the diameter of the inlet piping is 15 cm, whereas that of the discharge piping is 10 cm. Determine the mass flow rate in kg/s.

• 38.3333

• 50

• 50.1251

• 83.1831

A centrifugal pump compresses 2300 liters/min of water from 98 kPa to 300 kPa. The inlet and outlet temperatures are 25°C. The inlet and discharge piping are on the same level, but the diameter of the inlet piping is 15 cm, whereas that of the discharge piping is 10 cm. Determine v1 and v2.

• v1=2.1692m/s ; v2 = 4.8807m/s

• v2=2.1692m/s ; v1 = 4.8807m/s

• v1=1.2692m/s ; v2 = 4.8807m/s

• v1=2.1692m/s ; v2 = 8.4807m/s

A centrifugal pump compresses 2300 liters/min of water from 98 kPa to 300 kPa. The inlet and outlet temperatures are 25°C. The inlet and discharge piping are on the same level, but the diameter of the inlet piping is 15 cm, whereas that of the discharge piping is 10 cm. Determine pump power.

• 10.9 kW

• 8.1 kW

• 9.4 kW

• 7.8 kW

The weight of a bridge crane plus its load equals 100 metric tons (1 metric ton= 1000 kg). It is driven by a motor and travels at 1.17 m/s along the crane rails. Determine the energy that must be absorbed by the brakes in stopping the crane.

• 68.4 kJ

• 64.8 kJ

• 86.4 kJ

• 46.8 kJ