Physical Science, Module 9, An Introduction to the Physics of Motion, Part B

Part A of Module 9.
Experiment 9.3, Measuring Height with a Stopwatch

We went by the cousin's house yesterday, and they took turns dropping a ball from a certain point on the treehouse while timing it with a stopwatch.  We marked the railing so they would all drop it from the same point.  They had a few practice tries, then dropped it four times each.  We dropped the highest and lowest times, and kept 10 to get an average.  The average time was .861 seconds.
Using the formula found on p. 223, Distance = ½ x (acceleration) x (time)², they had to figure the distance from the rail to the ground.

"The acceleration due to gravity for any object 
is 9.8 meters/second ² in metric units and 32 feet/second² in English units." Since we measure in feet, we used 32 feet for the acceleration.
Distance = ½ x (32 feet) x (.861 seconds)²
The distance calculated to be 11.86 feet, or about 142 inches.
The actual measured distance was 12.58 feet, or 151 inches.
Pretty good, I'd say!  =)
P.S.  Cousin C wasn't in these pics, although he did participate.  He was cleaning some fish!


We calculated the distance from the treehouse rail to the ground, and went over the other kinds of problems in this Module.  I gave them extra practice problems to do before the Study Guide and Test.
I had the corresponding # of the Exercises and On Your Own problems written on the practice page so they'd know where to look if they couldn't remember how to do a problem.