Physics 325 Spring 2011 Problem Session 10

Physics 325 Spring 2011 Problem Session 10 - E is a...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
Physics 325 Spring 2011 Discussion 10 April 11, 2011 A one-dimensional system has the Lagrangian: L = 1 2 m ˙ x 2 + k 2 x 2 , where k is a positive constant. (a) Write down the equation of motion. (b) Let G = ± m ˙ x 2 - k x 2 ² t - mx ˙ x. Take the time derivative of G , and show that it is zero by using the equation of motion. Note that the quantity inside the parantheses is proportional to the energy. (c) Since the Lagrangian does not have explicit time-dependence, the energy
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: E is a constant of motion. Suppose that we have the initial conditions x (0) = R , and x (0) = 0 . Solve for x ( t ) . Hint: If you use the fact that E and G are constants of motion, you can solve for x ( t ) without having to solve any differential equation. (d) When will the particle reach the origin?...
View Full Document

Ask a homework question - tutors are online