For a simple pendulum, what primarily determines its natural frequency of swinging?
Answer
The length of its string or rod.
For a simple pendulum, its natural frequency—how fast it swings back and forth—is determined primarily by the length of its string or rod; a shorter pendulum swings faster.

Related Questions
What fundamental condition causes resonance amplification?What primarily dictates a physical object's natural frequency ($\omega_0$)?How does the energy buildup occur during resonance?What effect does damping have on the resonance peak height?What characteristic defines systems exhibiting low damping?How is resonance exploited in a radio receiver?For a simple pendulum, what primarily determines its natural frequency of swinging?Which statement correctly distinguishes the cause from the effect of resonance?Why is recognizing all significant vibration modes critical in engineering analysis?What does designing a system for a high Q-factor imply?