In this animation the pendulum is the same as Animation 1 (the net force on the bob is shown as a green arrow), the spring has a spring constant of 1.30666 N/m, and the mass of the red ball...In this animation the pendulum is the same as Animation 1 (the net force on the bob is shown as a green arrow), the spring has a spring constant of 1.30666 N/m, and the mass of the red ball attached to the spring is 2 kg (the net force on the red ball is represented by the blue arrow).