imagine we provide a driving force pushing the mass down throughout its motion. Which of the following will increase the amplitude of the mass-spring system? (It is not possible to change the amplitude of the mass-spring system.) Applying a force at 1/3 its natural frequency You Answered Applying a force at its natural frequency Applying a force at 3x its natural frequency Applying a force at 1/2 its natural frequency Applying a force at 2x its natural frequency