g = -9.81
KE = 0.5*mass*Length^2*Velocity^2
PE = -g*mass*(Length*(1-cos(angle)))
Total_Energy = KE+PE
angle(t) = angle(t - dt) + (chg_angle) * dt
INIT angle = initial_angle
chg_angle = Velocity
Velocity(t) = Velocity(t - dt) + (Ang_Acceleration) * dt
INIT Velocity = 0
Ang_Acceleration = restoring_force/mass
initial_angle = 2*pi*initial_angle_in_deg/360
initial_angle_in_deg = 10
Length = 1
mass = 2
restoring_force = mass*g*sin(angle)/Length

Time Specs