EK Physics #177 - Confused

[ilovemcat]

---

Members don't see this ad.

Here's the question: A 6 kg bowling ball experiences a force due to gravity that is 2,000 times greater than the gravitational force experienced by a 3 g ping-pong ball. Which of the following properties explains why they fall at the same rate?

A. momentum
B. weight
C. inertia
D. size














Answer is: C Inertia - But the reason why I'm posting this is because I'm confused. I disagree with all the answers. From my understanding, Acceleration of a projectile is independent of its mass. I don't really understand why they're emphasizing the need to increase the force of the larger projectile when the speed of both objects is dependent on the acceleration (which remains relatively constant).

Unless both projectiles were on two different planets with different accelerations, but even then, what good would increasing the force do if the gravitational accelerations doesn't change (given the distance is negligible).

I know I'm over-anaylzing this, but this is a fundamental concept in a lot of problems, and I'd hate to miss them based on something I'm misunderstanding.

EDIT: -- I'm making the assumption there's no air resistance. Maybe thats where the confusion lies.

 

[Rabolisk]

The question is trying to test the relationship between force and acceleration. Two Objects of different inertia (mass) can undergo same acceleration due to different forces. As the MCAT likes to say, C is the best answer, even if the question is awkward.

The reason that gravitational acceleration is independent of mass is because gravitational force is directly proportional to mass or inertia.