by Gretchen McDougall and Ellen Wright
Do you know what these equations stand for? F = ma or [30(W/31) = 40(T/2)]Ei (Answers at the end of the article.)
Rob Kashima’s eighth-grade science students at in Half Moon Bay understand what they mean (one a law of motion in physics, and the other a scoring rubric).
On May 27, Kashima's students learned just how well they were able to apply what they learned in class at the school's Egg Drop contest, where protective containers they had designed to prevent the eggs from breaking in a fall were put to the test.
The class was divided up into teams of two. Each pair of student engineers designed a container according to project specifications designed to protect the raw eggs from cracking or breaking when dropped from a considerable height onto a hard surface.
Battalion Chief Ari Delay provided use of one of the department's fire engines with an extension ladder, so that the containers (with the eggs nestled inside, of course) could be dropped from a considerable height.
In front of a crowd of students on the Sea Crest campus, firemen climbed the ladder and dropped the containers one by one. Each container was dropped twice. On the first drop, ten teams’ containers were thrown from less than a 45 degree angle. Only two eggs cracked! On the second and final drop, eight containers were thrown from an angle greater than 45 degrees. All eight eggs survived the second round.
Students were assessed on design, the extent to which the container landed within a certain area or target, the height of the drop, and whether or not their eggs survived the fall. Based on this criteria, Andrew Tom and Austin Macdonald were named the winners.
For the students of all grade levels who were in the audience, watching the event was an opportunity for the principles of physics to come alive in front of their very eyes. Students enjoyed the event so much that Sea Crest School is considering expanding the contest to include all Coastside 8th graders next year.
Answers: F = ma is Newton’s Second Law of Motion, force = mass times acceleration. The second law says that the acceleration of an object produced by a net (total) applied force is directly related to the magnitude of the force, the same direction as the force, and inversely related to the mass of the object. Newton’s Third Law of Motion is also involved in this project—for every action there is an equal and opposite reaction. The score was calculated using the formula above. If the egg cracked, the team’s score was zero. The lowest non-zero score won.
