Answer: friction has no role to play in this case. because friction usually occurs between to parts which come in contacts. examples (a)our joints in the human body (b)two mechanical parts (shafts).
Explanation:
However what this topic relates to is gravity. The pebble and paper both weigh one gram, but have different density this is the sole reason why if both are drop from same height the pebble would reach the ground faster than the paper because it is more denser. unlike the paper with a lesser density which would take a longer time to reach the ground.
