Final answer:
When a vibrating structure is pushed at its natural period, it resonates, meaning its oscillations increase in amplitude with each push. Resonance happens due to the periodic driving force matching the system's natural frequency, maximizing energy transfer and amplifying motion.
Step-by-step explanation:
When a vibrating structure is given further pushes that are also at its natural period, the structure tends to resonate. Resonance occurs when a periodic driving force acts on a system at a frequency that matches the system's natural frequency. During resonance, the amplitude of the oscillations will increase with each push, making the oscillations larger as long as the driving force continues at that frequency. This is similar to pushing a child on a swing; if the pushes match the natural frequency of the swing's back-and-forth motion, the child will swing higher with each push.
It's important to note that when the driving frequency is not equal to the natural frequency, the system doesn't resonate, and energy is transferred less efficiently. Therefore, the amplitude of the oscillations will be smaller compared to when resonance occurs. An example of this can be seen with a paddle ball suspended from a finger. When moved at its natural frequency, the ball oscillates with increasing amplitude, demonstrating resonance.