Finding potential U from sum of forces F

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SUMMARY

The discussion revolves around determining the potential energy associated with a force field defined by its components: Fx = 2axy + by² + 6cz, Fy = ax² + 2byx, and Fz = 6cx. To establish whether the force is conservative, the condition F x ∇U = 0 must be verified. The potential energy U can be derived using the relationship F = -∇U, and the work done by the force during particle movement from the origin to a specified point can be calculated using the work integral applied to the three force components. The participant also inquires about the vector nature of U and the integration process for the components.

PREREQUISITES
  • Understanding of vector calculus, particularly gradient and divergence.
  • Familiarity with conservative forces and potential energy concepts.
  • Knowledge of work-energy principles in physics.
  • Ability to perform multivariable integration.
NEXT STEPS
  • Study the conditions for a force to be conservative in vector fields.
  • Learn how to compute potential energy from force fields using F = -∇U.
  • Explore the work integral in three dimensions for conservative forces.
  • Investigate the implications of dot products in vector calculus, particularly in the context of force and displacement.
USEFUL FOR

Students in physics, particularly those studying mechanics, as well as educators and tutors who assist with problems involving forces, potential energy, and vector calculus.

Geranimo
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< Mentor Note -- Thread moved to Homework Help from technical Physics forum >[/color]

Hi, I had an exam and I had this question:

A force acts on a particle of mass m, and its components are:

Fx = 2axy + by2 + 6cz
Fy = ax2 + 2byx
Fz = 6cx

a) Does this force is conservative? Show your calculations.
b) Find the potential associated with this force. (this one cause me trouble)
c) Calculate the work done by the force when the particle moves from the origin
at x0, y0, z0.

For a) we need to verify that F x ∇U is zero,

but for b) I don't know if I had to use (minus) the work integral or F = -∇U

c) One only had to apply the work integral to the 3 components.

Also, does U works like vectors? I mean, in b) can I do 3 work integrals for x,y,z and sum back? Or I need to integrate the 3 forms of F = -∇U?

Thanks.
 
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What happens if you dot the equation ##\vec{F}=-\vec{∇} {U}## by the differential position vector ##\vec{ds}=\vec{i}_x dx+\vec{i}_y dy+\vec{i}_z dz##? What does the right hand side look like?

Chet
 

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