Engineering, 24.02.2020 23:32 S28073161
A 0.54-oz model rocket is launched vertically from rest at time t = 0 with a constant thrust of 0.9 lb for 0.3 s and no thrust for t > 0.3 s. Neglect air resistance and the decrease in mass of the rocket.
Determine (a) the maximum height h reached by the rocket, (b) the time required to reach this maximum height.
Answers: 2
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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
A 0.54-oz model rocket is launched vertically from rest at time t = 0 with a constant thrust of 0.9...
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