Question

FIGURE P6-65 6-66 Indiana Jones needs to ascend a 10-m-high building. There is a large hose filled with pressurized water hanging down from the building top. He builds a square platform and mounts four 5-cm-diameter nozzles pointing down at each corner. By connecting hose branches, a water jet with 15-m/s velocity can be produced from each nozzle. Jones, the plat- 150 kg. Determine (a) the minimum water jet velocity needed to raise C the system, (b) how long it takes for the system to rise 10 m when the water jet velocity is 15 m/s and the velocity of the rplatform at that moment, and (c) how much higher will the momentum raise Jones if he shuts off the water at the moment the platform reaches 10 m above the ground. How much time does he have to jump from the platform to the r) form, and the nozzles have a combined mass of roof? Answers: (a) 13.7 m/s, (b) 3.2 s, (c) 2.1 m, 1.3 s D-5 cm 15 m/s

Answer 1