Classical Dynamics of Particles and Systems · Problem 7-41

Central-Force Motion — Marion & Thornton

Physics — Mechanics · lagrangian-shortening-pendulum-small-oscillations

Problem

A pendulum of length

b

and mass bob

m

is oscillating at small angles when the length of the pendulum string is shortened at a velocity of

\alpha

(

db/dt = -\alpha

). Find Lagrange's equations of motion.