(adsbygoogle = window.adsbygoogle || []).push({}); Lagrangian Dynamics problem -- need help with setup

Here's the problem:

A simple pendulum of length b and bob with mass m is attached to a massless support moving horizontally with constant acceleration a. Determine the equations of motion.

For the pendulum, x = b sin theta and y = b cos theta (Which of these equations should I use? y = b cos theta?)

For the support, x = (v0)t +.5a*t^2 - b sin theta? Is this correct?

Kinetic energy is 1/2 m (x'^2+y'^2), correct?

Potential energy is U=mgy.

If my equations are wrong, could someone tell me why and how to correct them? Your help is greatly appreciated!!!

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# Homework Help: Lagrangian Dynamics problem - need help with setup

**Physics Forums | Science Articles, Homework Help, Discussion**