Pick up a ball and drop it on the floor from shoulder height. 2. Name the parts of the system.
3. Name something that is NOT part of the system.
4. Thinking about the system, why is it important to name "air" as part of the system?
5. Draw and label the system and include all of the parts. You may have to get creative with this one!

2. The system will be defined by all the parts that act directly on the object, and the object itself.

So the parts are:

The ball.

The air.

The ground. (because this limits the motion of the ball)

The gravitational force (the force that pulls down the ball)

Why is it not the hand or you a part of the system? Because the phenomena is "a ball being dropped" the only action that you do in the ball is release it (you do not impulse it or anything) and we have our time t = 0s, when the ball is dropped, so the hand that was holding the ball is not in the picture for t ≥ 0s, then it is not part of the system.

3. Using what i wrote above, your hand is not in the system.

4. The air is important because it put resistance to the motion of the ball, if there was void, the ball would reach the ground in less time.

5. It is really hard to draw in a computer, so i will give a rough sketch of the system in this case:

Where: g = gravitational force.

           H =  initial height of the ball, which is really important for this problem.

well, i believe that the answer is 2. : 3