Arock at rest falls off a tall cliff. what is the rock's velocity as the rock hits the ground 3.5s later

There are multiple tuning forks present in the room, and annie strikes one with a natural frequency of 400 hz. which of these other tuning forks will begin to vibrate through resonance and make the sound louder? a 200 hz tuning fork a 400 hz tuning fork a 800 hz tuning fork a 1600 hz tuning fork