Where Could the Error Be in My Momentum Equation Calculation?

  • Thread starter Thread starter MMCS
  • Start date Start date
  • Tags Tags
    Momentum
Click For Summary
SUMMARY

The forum discussion centers on identifying errors in a momentum equation calculation related to fluid dynamics. The user reports an inaccuracy of approximately 2000N in their results. Key points raised include the potential misuse of the volume flow rate (.355 instead of .335), the accuracy of velocity term signs in the Bernoulli equation, and the consideration of mass in calculating gravitational force. Additionally, clarifications regarding the orientation of the pipe and the nature of the inlet pressure as "static" are noted.

PREREQUISITES
  • Understanding of fluid dynamics principles, specifically the Bernoulli equation.
  • Familiarity with momentum equations in physics.
  • Knowledge of volume flow rate calculations.
  • Basic concepts of gravitational force and mass considerations in fluid systems.
NEXT STEPS
  • Review the Bernoulli equation and its application in fluid dynamics.
  • Study the impact of volume flow rate on momentum calculations.
  • Learn about the significance of static pressure in fluid systems.
  • Examine case studies involving gravitational force calculations in fluid dynamics.
USEFUL FOR

Students and professionals in physics, engineering, and fluid dynamics who are troubleshooting momentum calculations and seeking to enhance their understanding of fluid behavior in various systems.

MMCS
Messages
151
Reaction score
0
I have attached the question and working out as i would lose the format. The answer i arrive at is innacurate by 2000N approx from the correct answer, If anybody could look at my working out and point out any mistakes i would appreciate it as i have been on this for hours and can't see the mistake

Thanks
 

Attachments

  • working.png
    working.png
    33.7 KB · Views: 477
Physics news on Phys.org
A couple of things: Did you use .355 instead of the given .335 for the volume flow rate when calculating the speeds c1 and c2?

In the Bernoulli equation, did you get the signs of the velocity terms correct?

I'm not sure, but shouldn't you use the mass of just the water rather than the total mass of water and pipe (240 kg) for the gravity force on the water in the equation for Fy?

[EDIT: To me, the question is not very clear as to whether the pipe bends upward or downward.]

[EDIT: Also, the pressure given at the inlet is given as "static".]
 
Last edited:

Similar threads

  • · Replies 10 ·
Replies
10
Views
2K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 2 ·
Replies
2
Views
1K
  • · Replies 18 ·
Replies
18
Views
2K
  • · Replies 17 ·
Replies
17
Views
1K
  • · Replies 10 ·
Replies
10
Views
2K
Replies
3
Views
2K
  • · Replies 10 ·
Replies
10
Views
1K
  • · Replies 25 ·
Replies
25
Views
2K
Replies
3
Views
1K