Today was the second day of the gravity drop lab. Students attempted to prove, using our simple equipment, that Earth’s acceleration due to gravity is indeed 9.8 m/s per second. This time, they measured the marble’s “time of fall” and compared it to the marble’s “top speed” at the end of the fall. They graphed their data, and most groups found a slope close to 9.8.

Of course, doing the experiment in a room full of air with shaky equipment didn’t yield perfect results. But that’s not the point. The point is that we now know how scientists solved the problem of measuring Earth’s gravity in the first place!

Also, as a reward for those of you who check the website every night, I am offering a prize tomorrow to the first person who sees me during homeroom and whispers the password “lunar.” Goodnight, everyone!

January 6 – Gravity Drop Day 2 (pg403)