Students Learn ‘Crane Math’

By SUZANNE ARENA

The high school had to replace a 2,000+ pound. air conditioning (AC) unit this week. So, how do you move such a unit? With a crane, of course. But will any crane do? The short answer is “no.” The long answer involves A LOT of math and students at JCHS got to figure out some of the math and see it in action last Wednesday.

Students took a protractor to measure angles of the crane at different points in the transport of the AC unit. When picking up the unit from the ground, the top angle was less than 30 degrees, but once the unit was ready to be set gently on the roof, the top angle was nearly 80 degrees. Students were able to watch the right triangle being transformed each time the crane operator had to make an adjustment for proper placement of the unit. Students discussed and answered questions about WHY the crane arm length would make a difference in the angles and in placement of the unit and why a crane was even necessary (instead of other methods for moving.)

In addition to geometry discussions, physics principles were applied and discussed in class. For example, the crane used was a “100 ton crane” and the crane operator still had to load 39,500 pounds of counter-weight to be able to lift the unit. Students questioned needing so much counter weight for lifting “only” 2,000 pounds. Each question brought more discussion and more questions. The old unit weighed about 2,500 pounds and the new unit weighs 2,330 pounds. Students discussed many factors that could address the question.

Students worked together to come up with different approaches to solve the many variables involved in something that to the naked eye seems like a simple process. By the end of the day, students had a much better understanding of the many decisions that have to be made, and calculations to be considered, when approaching “real-life” problems.