Did I do this fluids problem right? A find the gallons/min gushed by a fountain

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The kinetic energy of the water leaving the pipe is equal to the potential energy it gains when it reaches its maximum height.In summary, using the equations for pressure and energy conservation, we can calculate that the fountain is using approximately 5.66 gallons per minute.
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lalalah
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1. A fountain sends a stream of water straight up into the air to a maximum height of 4.23 m. The effective area of the pipe feeding the fountain is 5.38 x 10^-4 m^2. Neglecting air resistance and any viscous effects, determine how many gallons per minute are being used by the fountain. (1 gal = 3.79 x 10^-3 m^3)



Homework Equations



F = (mv^2)/r
F = P * A
P = density * g * h
m = density*(Ah)

The Attempt at a Solution



P= 1.013x10^5 * pgh
P= 1000*9.8*4.23 + 1.013x10^5
P= 142754 Pa

PA = F
PA = (mv^2)/r

r = (Area/pi)^(1/2)
r= .013086 m

mass = 1000 * area * 4.23
mass = 2.27574 kg

142754 Pa * (5.38 *10^-4 m^2) = (2.27574 kg * v^2)/.013086 m
v = .66455 (m/s multiply by area

.66455 * (5.38 * 10^-4) = .0001926 m^3/s

divide v by 3.79 * 10^-3 m^3, then multiply by 60 seconds

5.66 gal/min



this is so obviously wrong, but I've tried this prob beyond five times already and am at wits end... can anyone steer me in the right direction? thankkkks!
 
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  • #2


lalalah said:
F = (mv^2)/r

That equation isn't relevant here, since it applies to circular motion and centripetal force.

How about trying energy conservation?
 
  • #3


I cannot determine if your solution is correct without seeing your work and calculations. However, I can provide some guidance to help you check your work.

First, it's important to carefully read and understand the problem. In this case, the problem is asking for the gallons per minute of water being used by the fountain, not the velocity or force of the water. So your final answer should be in units of gallons per minute.

Next, make sure you are using the correct equations and units. The equations you listed are relevant, but you need to choose the appropriate ones for the problem. For example, the equation F = (mv^2)/r is used to calculate the centripetal force on an object moving in a circular path. This may not be relevant to the problem at hand.

Also, pay attention to units and make sure they are consistent throughout your calculations. For example, in your calculation for mass, you used the density of water in kg/m^3, but then you converted the volume to m^3/s, which is not a unit of volume. This could be why your final answer is off.

Finally, check your calculations and make sure they are correct. A small mistake in one step can throw off your final answer. If you are still having trouble, try breaking down the problem into smaller, simpler steps and double check each step as you go. And always make sure your answer makes sense in the context of the problem.

I hope this helps and good luck with your problem!
 

FAQ: Did I do this fluids problem right? A find the gallons/min gushed by a fountain

How do I know if I solved the fluids problem correctly?

There are a few ways to check if you have solved the fluids problem correctly. First, make sure you have accurately identified and labeled all of the given information, such as the flow rate and volume. Next, double check your calculations and make sure you used the correct formula. Finally, compare your answer to the given solution or ask a peer or instructor to review your work.

What units should I use when finding the gallons per minute gushed by a fountain?

The most common units for flow rate are gallons per minute (GPM) or liters per second (LPS). However, make sure to use units that are appropriate for the given problem. For example, if the fountain is continuously running for one hour, it would be more appropriate to use gallons per hour (GPH) as the unit for flow rate.

How can I determine the flow rate of a fountain if I only know the volume of water it holds?

In order to determine the flow rate of a fountain, you will need to know both the volume of water and the time it takes to fill that volume. Once you have those two pieces of information, you can use the formula: flow rate = volume / time. Make sure to convert your units to be consistent with the given time frame.

Can I use the same formula to find the flow rate for different types of fluids?

Yes, the formula for flow rate can be used for any type of fluid, as long as the units are consistent. However, keep in mind that the viscosity (thickness) of the fluid may affect the flow rate. For example, honey will have a lower flow rate than water due to its higher viscosity.

What factors can affect the flow rate of a fountain?

There are a few factors that can affect the flow rate of a fountain. These include the size and shape of the fountain's nozzle, the pressure of the water source, and the viscosity of the water. Additionally, any blockages or restrictions in the fountain's plumbing can also impact the flow rate.

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