1. B

    Moving garden hose - why does the water travel shorter distance

    We all know a garden hose. Keeping is stationary it has a certain throw length based on nozzle exit velocity and angle of the nozzle. If you start swinging/rotating the hose e.g. in the horizontal plane, then the throw length decreases significantly - but what are the physics behind this and can...
  2. G

    Why does resonant frequency become lower as water is added to a bottle?

    Hello! I am an IB student currently working on my Internal Assessment, which is an investigation on the relationship between the volume of water in a glass bottle and the frequency of the sound made when the bottle is hit with a metal knife. I have collected my data, and found that the...
  3. T

    Evaporating Water with a Boiler Type Vessel

    I am attempting to evaporate water to the atmosphere with a boiler type vessel. Normal operating pressure of the vessel would be 5 psig. How much water could potentially be evaporated? Also, what issues come to mind with this concept?
  4. H

    boat moving in a river

    I am looking for an explanation on how to calculate this situation. You are floating in a boat in calm water some distance D miles from a dam. A gate is opened at time T. You know the width and depth of the river, the size of the gate and how far above the low side of the dam it is located...
  5. A

    How much heat is required to turn ice into water vapour?

    This is the question: "How much heat is required to turn 1.5 kg of water ice at a temperature of −25°C into 1.5 kg of water vapour at 150°C? (to 2 s.f and in MJ) [cice = 2090 J kg−1 K−1, cwater = 4190 J kg−1 K−1, cwater-vapour = 2010 J kg−1 K−1, Lvap-water = 2256×103 J kg−1, Lfus-water =...
  6. E

    Water-air heat transfer

    Experiment: The air currents of two large domestic fans were directed toward the water surface of a 50-gallon tank while the ambient temperature was 88°F. If at the beginning of the experiment the water was at 77°F, why did this temperature drop? Shouldn't it have been the other way around...
  7. J

    Water Heater - useful energy content

    Hi, i´m developing a project and have some questions about thermodynamics I have this table with data. And this is what variables are: -useful water flow rate (f) means the minimum flow rate, expressed in litres per minute, -useful water temperature (Tm), means the water temperature...
  8. R

    Heat transfer between flue gas and feed water?

    I need to determine the temperature of flue gas in a fire tube boiler. Tube inlet gas temperature, T1 = 1045 deg.C Saturation water temperature, tsat = 186 deg.C Flue gas temperature, t2 = ? 2 equations to be used here: Q = U.A.LMTD -------------(1) Qg = Mg.Cg.(T1 - T2) ------(2)...
  9. P

    Relationship Between Velocity and Height of Water

    Help! Relationship Between Velocity and Height of Water Hello, I have been given a lab paper to do on the relationship between the velocity of water leaking from a hole in a bottle and the height of water above the hole. We are supposed to focus on analyzing and finding the relationship between...
  10. T

    Water heater and mass flowrate

    Hello everybody! I was thinking: if I change the mass flow rate (by opening the tap when I'm going to take a shower) the water will take more or less time to heat? I've proceeded as follows: by making the heater my control volume: \dot{Q}=\frac{d(nU)}{dt} + \dot{n}(H^{out}-H^{in})...
  11. P

    Impact of a jet of water

    Hi, I would like some help with the following problem: "A jet of water issues from a nozzle, of diameter h_1=0,102 m (and depth b=1 m), at a speed U_1=2,02 m/s. The jet strikes a flat plate of mass M=2,05 kg, as shown in figure, and it breaks into two jets of equal speed and diameter h_2=0,122...
  12. C

    Fluid-dynamics of water between two containers

    I have a rigid container connected to a soft bag as in the picture below. Water is pumped with a peristaltic pump in the rigid reservoir through a pipe of 6 mm diameter on the top. From the rigid container, water goes in the soft bag through a hole of 9.5 mm. The rigid container has a small hole...
  13. T

    Water Cannon

    EDIT B: Ok, this is what I did. I got rid of the rest to avoid confusion. The question: A cannon fires water such that it is a cylinder with a radius of 10 cm, and at an angle of 21.8 degrees. If the water lands 10 km away after 30 minutes, how much force is behind it, and how much pressure is...
  14. J

    Speed of sound in water

    For a science project, I need to measure the speed of sound in water. Obviously, I don't have any fancy equipment to do this so I came up with a set up I'm not sure will work: I have a PVC cut to 29.8 cm long. I attached two thin pieces of glass (a screen cover for a phone) on each end to...
  15. C

    Water flows into a pool how long will it take to fill?

    Water flows through a 2.3-cm-diameter hose at 4 m/s. How long, in minutes, will it take to fill a 750 L kiddie pool?
  16. O

    Determine the density of oil and water using a u tube

    Hi, I have a question within physics practical, so I hope your help for solve this priblem. When I do this practical my text books says we should add high density liquid first and then lower density liquid. Also when we messure the heights of the liquids (due to pressure) if I want to...
  17. Z

    Airtight pot with water at 200 degrees celcius

    New to the forum, so might be posting in the wrong subforum. Not sure this is advanced thermodynamics, but it is a university course so... Im having some issues with a problem: You have an airtight pot (closed) with an inner volume of 10L. The pot contains 5kg water (no air is in the...
  18. O

    Mass flow rate of water in a hydraulic turbine

    Hello again. I have another problem that I'm working on: The intake to a hydraulic turbine installed in a dam is located at an elevation of 10 m above the turbine exit. Water enters at 20 C with negligible velocity and exits from the turbine at 10 m/s. The water passes through the turbine...
  19. B

    Rock falls in water

    A rock of mass m is at a high h at rest. Under this height there is a container of water of mass M, deep d. The rock, the water, the air have the same temperature (condition 1). Find the variations of internal energy, the heats and the works transferred in the system rock+water from the...
  20. U

    How to calculate the conditions for water suction using pressure difference.

    I want to make a container with a low pressure inside it to pull water from a reservoir upward using a pipe, How do I decide on the height, the required pressure difference and the relevant flow rate?