The original write-up for this activity was on the
Thursday's Classroom website (http://www.thursdaysclassroom.com), which
has now gone offline. The activity can be used as a demonstration, a hands-on
activity or an in-class lab, and has that "messy factor" which
will be sure to get students of all ages involved!
- Large aluminum roasting pan
- Cocoa or hot chocolate powder
- Large bag of white flour
- Projectiles of various sizes and densities (balls, rocks, marbles,
- Garbage bags
Note: For a student lab, you will need one set of
above per group of 4 students.
- Cut open a garbage bag and spread on the floor. place the roasting
pan on top.
- Fill the roasting pan about 3/4 full with white flour.
- Using the sifter, sprinkle a thin, even layer of cocoa/hot chocolate
powder on top of the flour.
- Drop projectiles into the roasting pan and observe the craters, as
well as the rims of mountains around the edges of the craters, and the
streaks or rays that can fan out from larger craters!
- This can be repeated as often as you like - just flatten out the flour
and add a new top layer of cocoa.
- Have the students predict what will happen
- Have the students draw their observations of what happens
- Knowledge of lab variables and controls
- Vary the height of the dropped objects, and measure the ejecta.
- Vary the diameter of the dropped objects, and measure the ejecta.
- Vary the density of the dropped objects and measure the ejecta.
- Feeling adventurous? Build mountains and hills/valleys, and then bombard
them with projectiles!
Things to watch out for:
- Flour can be very slippery on a tiled floor - be sure to clean up
- Students are sometimes tempted to throw their projectiles at the pan,
increasing the risk of injury in the classroom. Be careful!
Other Classroom Resources
Originally from http://www.thursdaysclassroom.com
Adapted by the
CASCA education Webteam, (2009)