Why does a tuning fork always ring at the same pitch?
Show answer & explanation
Answer: Its prongs' size, shape and metal set one natural note
Room temperature fixes its vibration speed — Temperature barely matters; warming a fork shifts its pitch by only a tiny fraction, and it doesn't lock anything in place. The note is set by the prongs' length, thickness and metal.
Its handle filters out every other note — The handle doesn't filter sound; it's a stem to hold, placed where the fork barely vibrates so your hand doesn't damp the prongs. The pitch comes from the prongs themselves.
Its prongs' size, shape and metal set one natural note ✓ — Every object vibrates most easily at natural frequencies set by its size, shape and material. A tuning fork's prongs are designed so one frequency dominates, and its higher overtones die away within moments, leaving a nearly pure tone.