Recent content by tomas123

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    Find the speed of water out of a nozzle

    I think I understand now.. I don't have time to type what I'm thinking atm, but I'll be back later to see if you agree with my newfound reasoning. Posting this because I don't want anyone to spend time explaining to me when I've figured it out :)
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    Find the speed of water out of a nozzle

    I don't think I did? If you set up the area around the pump as the control volume, with the area of pipe being equal before and after, whatever energy/second is transferred to the flow, will be in the form of Pressure * flow rate. Kinetic energy, internal energy and potential energy will be the...
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    Find the speed of water out of a nozzle

    For a scenario w/o a pump, such as an elevated reservoir or something, the flow rate would be determined by the area at the outlet and the pressure difference. For a pump scenario on the other hand, the flow rate is determined by the pump, no? When I do calculations for drill strings, their...
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    Find the speed of water out of a nozzle

    I made up the numbers. With a pump, you can get pretty much w/e Pressure & speed situation inside the pipe you'd like.. no? For the numbers I have, we can make up that upstream from where we are looking there is a 3 piston pump. The pistons have an area equal to A1 = π m2. To get P1 = 500 kPa...
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    Find the speed of water out of a nozzle

    Homework Statement Water is flowing through a nozzle with entrance data: P1 = 500 kPa V1 = 10 m/s A1 = π m2 ρ = 1000 kg/m3. Exit data: P2 = atmospheric pressure, assume 100 kPa to make numbers easy V2 = ? A2 = π (0.5)2 ρ = 1000 kg/m3 With what speed does the water exit the...
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    B Torricelli's Theorem: Speed of Fluid & Height of Opening

    Assuming Patm is correct to use, for a horisontal pipe with an opening to the atmosphere we would have: V12/2 + P1/ρ = V22/2 + Patm/ρ where 1 = somewhere downstream and 2 = directly outside the pipe If we assume the pipe has a constant area, the continuity equation gives us V1 = V2, leaving...
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    B Torricelli's Theorem: Speed of Fluid & Height of Opening

    Torricelli's theorem relates the speed of a fluid exiting an opening in a reservoir to the height of the opening relative to the top of the reservoir... V=√2gh https://en.wikipedia.org/wiki/Torricelli%27s_law As seen in the wiki-link provided, the equation is essentially a Bernoulli's...
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    What is the Magnitude of Acceleration?

    My prof. made me question what magnitude of acceleration is.. Is it acceleration without direction, i.e -6 m/s/s becomes 6 m/s/s or is it ΔV(speed)/Δt (Sorta like magnitude of acceleration is to acceleration what speed is to velocity)?
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    Maximum force on stacked boxes, when we don't want the boxes to slip.

    aah I get it! the sum of F on M1 is 9.8N. Divided by 3kg = 3.267 m/s2. Sum of F on whole system = force by rope - friction (7kg * 3.267 m/s2) +13.72 = force by rope 36.589 = force by rope Thank you!
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    Maximum force on stacked boxes, when we don't want the boxes to slip.

    I get: max tension = F2 = 23.52 N Friction F1 = μk * n = 0.2 * 9.8 *7 = 13.72 tension on string = sum of forces on string = F2 - F1 = 37.24 N The answer is supposed to be 36.6 N. What did I do wrong? I really appreciate the help!
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    Maximum force on stacked boxes, when we don't want the boxes to slip.

    Homework Statement There are two blocks stacked on top of each other. M2 is on top of M1. M1 = 3 kg. m2 = 4 kg. μs between the two boxes = 0.6. μk between m2 and the floor = 0.2. Using a rope, we exert a force T on m2, dragging both boxes 5m. What is the maximum force we can exert on m2, if...
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