A Basketball in Free Fall

A screenshot of our motion graphs.

We've been studying motion this week in class. We used an iOS app called Vernier Video Physics ($2.99 on the App Store) to analyze the motion of a basketball. Specifically, we tossed a basketball straight up into the air. The top graph shows vertical position vs. time, and the bottom graph shows the basketball's vertical velocity vs. time.

In the comments, answer one of the following questions (just one so other students will have a chance too):

1. How high above the ground was the basketball when it was first thrown?
2. Estimate the highest height attained by the basketball.
3. With what speed was the basketball initially launched (when it first left the student's hand)?
4. How long was the basketball in flight before it reached the apex of its trip?
5. In class, we calculated the slope of the bottom graph to be about 8.8. What are the correct units for this slope?

Finally, let's get lots of comments on this question:

1. The acceleration of gravity near the Earth's surface is known to be 9.8 m/s/s which is a little higher than the acceleration measured by our experiment. Why does it make sense that our particular basketball's acceleration was a little lower than ideally expected?

Welcome Back!

Photo by riekhavoc used with permission through Creative Commons.

Welcome to a new school year! As this is the first blog post of the school year, I'd like to keep it very short and very simple. Post a comment to one or both of the following questions:

1. What would you like to learn this year in physics? Are there any topics in which you're especially interested?
2. What are your academic goals this year?

I am eager to read what you think.