The rocket shown in Figure 4.31 was test-fired in a high-altitude test cell. Vacuum pumps were used to lower the ambient pressure in the cell to a simulated altitude of 80,000 feet. The following measurements were obtained from test data: Average thrust = 18,000 lb INTERFACE PANEL LOX INLET FUEL INLETS THRUST CHAMBER NOZZLE EXTENSION MAIN LOX VALVE TURBOPUMP TURBOPUMP EXHAUST MANIFOLD HEAT EXCHANGER MAIN LOX VALVE CHECKOUT VALVE MAIN FUEL VALVE THRUST CHAMBER GIMBAL BLOCK HYPERGOL MANIFOLD F-1 ENGINE MAJOR COMPONENTS Figure 4.30 Diagram for Problem 4.38. fuel ox 4'' 20'' Figure 4.31 Diagram for Problem 4.39. Homework Problems 131 Average chamber pressure = 860 psi Propellant consumption = 6400 lb Burning duration = 110 s Determine the following quantities from these data: (a) average specific impulse; (b) propellant characteristic velocity; (c) average thrust coefficient; (d) vacuum specific impulse; (e) chamber temperature, assumingM 20lb=lb mol; and (f) overall efficiency - this is the ratio of the measured and ideal thrust values (You may assume 1:2 in all calculations.)