Question

A bunch of feathers and a stone of the same mass are released simultaneously in air from a height.

1. Which of the two will fall faster and why? $\left[2\text{marks}\right]$
2. How will your observation be different if they are released simultaneously in vacuum? $\left[2\text{marks}\right]$

Answer 1

The stone falls faster because, the volume of stone is less than the volume of the bunch of feathers of the same mass, and hence, the upthrust due to the air on stone is less than that on the bunch of feathers.$\left[2\text{marks}\right]$

However, in vacuum, both shall fall together because there will be no upthrust. $\left[2\text{marks}\right]$