Total kinetic energy vs total potential energy of a system

[jimseng]

i'm confusing on the total kinetic energy and total potential energy of a system.
The system is like this :

A block of boby mass,M attached to a spring and damper, which moves to the right, with the end of a rod,m pivoted on the center of the block (rotating).
let x= displacement, J= Polar moment of inertia, L= length of rod

Is the
kinetic energy
= (1/2)M (dx/dt)^2 + (1/2)(J)(d/dt theta)^2 + (1/2)m{ dx/dt -[L/2][d/dt theta] cos theta }

Is it correct?

 

[jimseng]

I got the solution already!
Using vectors approach along with lagrange method can solve this problem easily!
:)