Consider a 3-stage rocket with the following design. First stage propellant mass 7100kg and structure 900kg. Second stage propellant mass 5400kg and structure mass 600 kg. Third stage: propellant mass 3000kg and structure 500 kg. The payload mass is 60 kg. The specific impulses for all the stages are 275s. In a test, the second stage failed to ignite after the first stage was burned out. So the NASA operator decided to discard the second stage and directly ignite the third stage. + Questions: What was the final velocity of this rocket?

4r-134a enters the condenser of a residential heat pump at 800 kpa and 50°c at a rate of 0.022 kg/s and leaves at 750 kpa subcooled by 3°c. the refrigerant enters the compressor at 200 kpa superheated by 4°c determine (a) the isentropic efficiency of the compressor, (b) the rate of heat supplied to the heated room, and (c) the cop of the heat pump. also, determine (d) the cop and rate of heat supplied to the heated room if this heat pump operated on the ideal vapor-compression cycle between the pressure limits of 200 and 800 kpa. (0.757, 4.37 kw, 5.12, 6.18, 3.91 kw)