Shelli is a student describing the resonance of a metal beam. she demonstrates that the sound dims when the beam is vibrated at a certain frequency.

what does she most likely say in response to the dimming sound?

Shelli will most likely say that the sound produced by the resonance of a metal is affected by the frequency at which the metal is vibrated. There is a certain frequency that will create a dim sound. If the frequency is changed to the right setting, the sound will intensify.

Is a  vector quantity  that refers to "the rate at which an object changes its position." imagine a person moving rapidly - one step forward and one step back - always returning to the original starting position. while this might result in a frenzy of activity, it would result in a zero velocity. because the person always returns to the original position, the motion would never result in a change in position. since velocity is defined as the rate at which the position changes, this motion results in zero velocity. if a person in motion wishes to maximize their velocity, then that person must make every effort to maximize the amount that they are displaced from their original position. every step must go into moving that person further from where he or she started. for certain, the person should never change directions and begin to return to the starting position.