In: Physics
Drop two sheets of notebook paper to the ground at the same time, one of them open and the other crumpled up tightly. Drop the crumpled sheet and a stone at the same time. Drop a pebble and a large stone at the same time. Explain the results.
Ans
There are two force acting on the object as it fall : gravity (in down direction) and air resistance(in up direction).
If air resistance is negligible all the objects hit the ground at the same time irrespective of the mass of the objects. As free fall acceleration = g for all objects.
1) Crumpled sheet and open sheet:
The crumpled sheet would reach the ground first. They both have the same mass, hence they would have the same acceleration in g in down direction but air resistance for open paper(large surface area against the air) is non negligible. Hence crumpled sheet reaches the ground first.
2) Crumpled sheet and a stone:
They would reach the ground at the same time. Both have the same acceleration g. and we can ignore the air resistance for both them.
3) pebble and large stone:
Again they would hit the ground at the same time. Both have the same acceleration and air resistance can be ignored.