Question

question #9
a student dropped several objects from a height of 2 meters. the student recorded the data in the table below.
object\tmass (kilograms)\ttime (seconds)
marble\t0.0200\t0.45
tennis ball\t0.0577\t0.75
piece of paper\t0.0045\t1.5
if the objects had been dropped in a vacuum, all of the objects would have fallen at the same rate and hit the ground at the same time. which of the following is the best explanation for why that did not happen in this experiment?
the student did not drop items that had the same mass. items will only fall at the same rate if they have the same mass.
the student must have an error in their data. they did not start each object from the same distance.
the student did not drop the items in a vacuum. so, each item had a different amount of air resistance based on its size and shape.
the student did not drop the objects from a large enough distance. so, they did not have time to reach terminal velocity.

Explanation:

In the presence of air, objects experience air - resistance which depends on their size and shape. In a vacuum, there is no air - resistance and all objects fall at the same rate regardless of mass, size or shape. Since the experiment was done in air, different air - resistances affected the fall times.

Answer:

The student did not drop the items in a vacuum. So, each item had a different amount of air resistance based on its size and shape.