21. In an ideal piano string, the only restoring force would be due to the tension in the string. 22. Ions in a quadrupole field experience restoring forces that drive them back toward the center of the trap. 23. Wang and Wen ( 1998 ) suggested the following expression to account for the asymmetric peak restoring force : 24. At sufficiently large displacements, the stiffness of the wing dominates to provide the restoring force that enables an oscillation. 25. However, at 0 } }, the mass has momentum because of the acceleration that the restoring force has imparted. 26. The restoring force provided by the nonlinear spring is then \ alpha x + \ beta x ^ 3. 27. A deluxe edition of the album, titled " Restoring Force : Full Circle ", was released on February 20, 2015. 28. The Drude model applies when the restoring force component is negligible and the coupling coefficient is generally the plasma frequency. 29. Averaged over all stars at x, this acceleration must equal the gravitational restoring force per unit mass F _ x. 30. If the expansion occurs too close to the surface the restoring force will be too weak to create a pulsation.
