Let us, therefore, describe the position of the pendulum by the angle it makes with the vertical, θ, and let α=d2θ/dt2 be the angular acceleration; we can then write the e...Let us, therefore, describe the position of the pendulum by the angle it makes with the vertical, θ, and let α=d2θ/dt2 be the angular acceleration; we can then write the equation of motion in the form τnet=Iα, with the torques taken around the center of rotation—which is to say, the point from which the pendulum is suspended.
