[Physics] How far can I spray water in a straight line from a pump knowing the pressure and flow rate

distancefluid dynamicspressurewater

I want to build a water gun (think super soaker) powered by a water pump.
If I know the flow rate and pressure of a pump, can I calculate how far a jet of water will go in a straight line, assuming wind is not a factor?

For example, pressure=115Psi with a flow rate of 5l /min would give how many meters?

Best Answer

Even ignoring the wind or air resistance, the water won't go in a straight line because of gravity. So you'd need an initial height (and an initial angle, if it's not horizontal) in order to figure out how far the water would go before hitting the ground.

The (initial) velocity (speed, really) could be figured out from Area * velocity = Volume / time. You gave the Volume/time as 5 L/min (300 L/s =.3 m^3/s). I believe you'd need the area of the nozzle (in m^2 would be good) and then you could solve for the velocity (in m/s) and use projectile motion to figure out when it hits the ground.

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