Question

Shown below are eight rocks thrown into the air. Ignoring air friction, rank the rocks according to the acceleration of the rock at the top of the motion, largest first.

a) 1, 2, 3, 4, 5, 6, 7, 8
b) 8, 7, 6, 5, 4, 3, 2, 1
c) 2, 4, 6, 8, 1, 3, 5, 7
d) 8, 6, 4, 2, 7, 5, 3, 1

Answer 1

All rocks thrown into the air have the same acceleration at the top of their trajectory, which is equal to the acceleration due to gravity (-9.8 m/s^2) on Earth, and thus cannot be ranked by acceleration at that point.

Step-by-step explanation:

When considering rocks thrown into the air, ignoring air friction, the acceleration at the top of their motion is due to the acceleration due to gravity, which on Earth is a constant -9.8 m/s2 (negative indicates the direction towards the Earth).

Regardless of the rock's initial velocity, mass, or the height it reaches, the acceleration at the top will be the same for all rocks. Therefore, for the eight rocks described in the scenario, their acceleration at the top of their motion would be identical. Thus, ranking these rocks based on acceleration at the top of the motion is not applicable because all the rocks will share the same acceleration value due to gravity.