|MadSci Network: Physics|
Dear Expert Assume a jet boat or personal water craft (JetSki, etc) has a movable propulsion nozzle. This nozzle can be moved up or down so that the water jet driving the boat forward can be either above the surface or below the surface of the water. Applying the same amount of power to the jet unit does the thrust increase or decrease when the jet nozzle is under the water surface and why? Further clarification. You are speeding along on your Person Water Craft (PWC) at 50 mph. Lets say the propulsion jet is above the water surface at this time, that is the propulsion water is exiting the nozzle above the water surface. Your PWC has a special nozzle that can be moved up or down. You keep the throttle at the same setting and you lower the nozzle so that the water jet is now under the water surface. What happens and why? Just assume drag stays the same. Thank you. Jason
Re: Jet boat thrust measurement. Above or below water surface
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