Explain what the wall switch does to make the lights go on in your classroom.

current and voltage can both be different in different parts of a circuit so it matters where you place the ammeter and voltmete

when two balls of the different masses are dropped from equal height, they reach the ground at the same time .this is because they experience the same acceleration.

the acceleration is independent of mass.

thus when they are dropped they will always maintain the same velocity and travel the same distance (neglect air resistance of course) at the same time.