collar_potential_energy.m

function [Total_potential_energy] = collar_potential_energy(x_C,theta)
m=0.5; %define mass
K=30; %define stiffness K
g=9.81; %define gravity constant
PE_g = m*(x_C)*g*sin(theta); %define gravity potential 
DL = 0.5 - sqrt(0.5^2+(0.5-x_C)^2);
PE_s=1/2*K *(DL)^2; %define spring potential 
Total_potential_energy= PE_g + PE_s; %total potential energy 
end