In an Air-Free Chamber,a Pebble Is Thrown Horizontally,and at the Same

Multiple Choice

In an air-free chamber,a pebble is thrown horizontally,and at the same instant a second pebble is dropped from the same height.Compare the times of fall of the two pebbles.

A) The thrown pebble hits first.
B) The dropped pebble hits first.
C) They hit at the same time.
D) We cannot tell without knowing which pebble is heavier.