Apologia Physics Prepping for Fall: Measurement

Measurement, metrics, and conversions.  The first module in Physics reviews these key skills.  Can the kid do math?  He is going to need a mastery of math and algebra to be successful in Physics.  I like to assess and review simultaneously.  I suggest Bowling for Density or Will a Bowling Ball Float?  The answer depends.  You can assemble a tape measure, bowling ball, bathroom scale, plastic trash can, water, and ice, while tasking the teens with the problem: Will a bowling ball float?  Typically, I start off coaching the group.
1. Will a bowling ball float?
2. What determines if something floats?  Here, the discussion should be about density.  Once kids say an object must be less dense than water in order to float, it's time for the next step.
3. What is the density of water?  Usually, one kid knows it's 1 g/ml.  If not tell them.
4.  Make sure the teens understand what density is: mass/volume.
5.  With density defined, ask how to measure volume, presumably with the formula for the volume of a sphere. Calculate the ball's volume.  (1 cubic centimeter equals 1mL.)
6.  Now, ask how to determine the mass of the bowling ball.  One of the kids will figure out how to weigh the ball by first weighing himself, then with the ball.  Girls will not weigh themselves in public.
7. Point out that the bathroom scale is in pounds.  The density formula is in grams.  1 lb. is 0.454 kg.  Let the kids convert the bowling ball's weight from pounds to grams.
8. At this point, the kids get a little lost.  Remind them to calculate the bowling ball's density (g/mL)
9. Is the ball's density more or less than water's density, 1 g/ml?
10.  Do it!  As a follow-up, drop a marble in the plastic bin.  A ten pound bowling ball will float; the glass marble will sink.  If time permits, get out a plastic cylinder, digital scale, and glass marble.  Use a piece of string to determine the marble's circumference and calculate its density, too.

It will take 45-60 minutes for this activity.  If you have a large group, walk the kids through the steps and distribute several bowling balls.  I have borrowed and purchased bowling balls.  Yard sales are good sources.  Allow time to test the ball's.  You may want to throw in ice.