Classical mechanics problem for a free particle

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SUMMARY

The discussion revolves around a classical mechanics problem involving a free particle of mass m moving in one dimension with an initial velocity v0. The key tasks include calculating the action I for the particle's trajectory, determining the trajectory x(t) under a new initial velocity v1 and constant acceleration a, and analyzing the action I(v1) for this new path. The problem emphasizes that the particle remains free with no potential energy, leading to specific equations of motion that must be derived and analyzed for maxima, minima, or inflection points.

PREREQUISITES
  • Understanding of classical mechanics principles, specifically Newton's laws of motion.
  • Familiarity with the concept of action in physics and its mathematical formulation.
  • Knowledge of calculus, particularly differentiation and its application in physics.
  • Ability to manipulate and solve equations of motion in one-dimensional systems.
NEXT STEPS
  • Study the derivation of the action principle in classical mechanics.
  • Learn about the equations of motion for free particles under constant acceleration.
  • Explore the concept of extremal paths in the context of variational calculus.
  • Investigate the implications of the second derivative test for action functions in physics.
USEFUL FOR

Physics students, educators, and anyone interested in advanced mechanics, particularly those studying classical mechanics and variational principles.

becks1
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Summary: The initial problem states: Consider a free particle of mass m moving in one space dimension with velocity v0. Its
starting point is at x = x0 = 0 at time t = t0 = 0 and its end point is at x = x1 = v0t1
at time t = t1 > 0. and this info is to do the 3 problems written out.

a) Calculate the action I for this path.
b) Now suppose that the particle has the same initial and final points in space and
time, but now has an initial velocity v1 6= v0 and a nonzero constant acceleration
a. Find a as a function of v1 and give the trajectory x(t). Note that this is still
a free particle with no potential energy, so x(t) will not satisfy the equations of
motion.
c) Find the action I(v1) for this trajectory, Show that dI/dv1 = 0 for the path
which solves the equation of motion. Is this path a maximum, a minimum. or an
inflection point of I(v1)?
 
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@becks1, please give relevant equations and show some attempt at a solution.
 
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