Engineering, 26.09.2019 18:30 adamflex

Arigid (constant volume) tank sealed by a valve initially contains 100 kg of air at a pressure of 100 kpa and 300 k. at time = 0, the valve for the air tank is opened in a controlled manner and air leaks out isothermally (constant temperature) of the tank at a constant mass flow rate of 1 kg/s. the valve is closed after 75 seconds. answer the following questions using the mass values calculated previously for the problem from lecture 3: a. the total change in internal energy of the air tank, in kj, if the specific internal energy for air is 214.1 kj/kg. b. the heat transfer of the process, in kj, if kinetic and potential energies are neglected and the specific enthalpy for air at 300 °c is 300.1 kj/kg.

Answers: 2

Show answers

Another question on Engineering

Engineering, 04.07.2019 18:10

Aloaded platform of total mass 500 kg is supported by a dashpot and by a set of springs of effective stiffness 72 kn/m. it is observed that when the platform is depressed through a distance x = 12.5 cm below its equilibrium position and then released without any initial velocity; it reaches its equilibrium position in the shortest possible time without overshoot. find the position and velocity of the loaded platform 0.10 sec. after its release. if a further load of 400 kg is added to the platform, find, i) the frequency of damped vibrations, and i) the amplitude of vibration after 2 complete oscillations, given that the initial amplitude is 15 cm.

Answers: 1

Answer

Engineering, 04.07.2019 18:10

Air is to be cooled in the evaporator section of a refrigerator by passing it over a bank of 0.8-cm-outer-diameter and 0.4-m-long tubes inside which the refrigerant is evaporating at -20°c. air approaches the tube bank in the normal direction at 0°c and 1 atm with a mean velocity of 4 m/s. the tubes are arranged in-line with longitudinal and transverse pitches of sl- st 1.5 cm. there are 30 rows in the flow direction with 15 tubes in each row. determine (a) the refrigeration capacity of this system and (b) pressure drop across the tube bank. evaluate the air properties at an assumed mean temperature of -5°c and 1 atm. is this a good assumption?

Answers: 1

Answer

Engineering, 04.07.2019 18:10

Ariver flows from north to south at 8 km/h. a boat is to cross this river from west to east at a speed of 20 km/h (speed of the boat with respect to the earth/ground). at what angle (in degrees) must the boat be pointed upstream such that it will proceed directly across the river (hint: find the speed of the boat with respect to water/river)? a 288 b. 21.8 c. 326 d. 30.2

Answers: 3

Answer

Engineering, 04.07.2019 18:10

Afluid flows with a velocity field given by v=(x/t)i.. determine the local and convective accelerations when x=3 and t=1.

Answers: 2

Answer

You know the right answer?

Arigid (constant volume) tank sealed by a valve initially contains 100 kg of air at a pressure of 10...

Questions