Vernier Software and Technology
Vernier Software & Technology

Maximum Tension of a Pendulum

If Ed Wyrembeck’s physics students were to engage in the thrillseeking venture of bridge swinging, they could do it without being concerned about the cable breaking. That’s because of an experiment the Howards Grove High School physics and calculus instructor conducted with 14 of his students last year. They determined that in order for someone to swing back and forth on a cable suspended from a bridge, the tension on the cable must be at least three times the weight of the person or persons hanging from the end of it.

“I designed a simple experiment to test the theoretical prediction that the maximum tension in a pendulum string swinging down from a 90-degree angle from the equilibrium position is equal to three times the weight of the pendulum bob.”

“I designed a simple experiment to test the theoretical prediction that the maximum tension in a pendulum string swinging down from a 90-degree angle from the equilibrium position is equal to three times the weight of the pendulum bob,” he explained, for those familiar with physics.

His efforts in proving his theory reaped handsome rewards. The National Science Teachers Association (NSTA), the world’s largest organization of science educators, headquartered in Arlington, Va., selected him as one of five recipients nationwide for its 2004 Teacher Awards Program. The program honors K-12 teachers, college professors, principals and others for their outstanding achievement and innovative programs in science education.

A teacher at Howards Grove High School for the past 19 years, he was one of three teachers to receive the Vernier Technology Award for educators at the high school level. Michael Farmer of South Carolina and Eric Muhs of Seattle, Wash., were the other two recipients.

One college professor and one middleschool teacher also received awards from NSTA. The awards were funded through the Vernier Company of Beaverton, Oregon.

Wyrembeck won his award for his innovative use of technology in the classroom. He created a microcomputer-based lab with five mobile computers on carts. The computers are equipped with probes, sensors, a motion detector and accelerometer.

“You need a high-speed computer and a force probe for this experiment,” he noted.

The Vernier Technology Awards recognize and reward the innovative use of data collection technology, using a computer, graphing calculator or other handheld data collecting device in the science classroom.

“NSTA awardees represent the best and brightest in science education.”

“NSTA awardees represent the best and brightest in science education,” said John Penick, NSTA president. “We congratulate these outstanding educators fort heir lifelong commitment to science education and for their innovative and creative approaches to teaching our students science.”

Wyrembeck and his wife Theresa attended a special banquet and award ceremony in Atlanta, from April 1-4, during the NSTA National Convention. He was awarded $3,000: a $1,000 cash award, another $1,000 for travel expenses to and from Atlanta, and $1,000 worth of vouchers to purchase Vernier science equipment: probes, sensors and software for his classroom.

“I am very pleased and grateful for this award, since there are only three high school teachers selected in the nation,” he said. “I consider myself very lucky.”

“But although my name is on the award, I could not have done this without the students, administrators and secretaries at school and without the whole Howards Grove community.”

“He came up with the idea for the experiment after watching a segment of a ‘Real Television’ program.”

He came up with the idea for the experiment after watching a segment of a “Real Television” program. The program involved a number of daredevils who were swinging from a suspension bridge in Florida. They attached a cable to a high bridge, then sat on a small support at the end of the stretched out cable and swung up and down on a simple pendulum.

“Unfortunately, the thrillseekers underestimated the maximum cable tension required to support and turn themselves on the pendulum bob, so the cable broke,” Wyrembeck said. “They did not factor in that the cable had to turn the pendulum bob. They didn’t have a strong enough cable.”

Fortunately, there were no fatalities in the accident. However, the thrillseekers were seriously injured with broken bones. The crew of a pleasure boat picked them up and took them in for treatment.

“The next day, I told my physics students about what I had observed on that TV program and asked them if they wanted to investigate the tension in a pendulum string,” Wyrembeck said. “They enthusiastically agreed, and that was the beginning of our first independent research project.”

“I did what any good physicist would do. I looked for some equations to guide my thinking.”

During the experiment, “I did what any good physicist would do. I looked for some equations to guide my thinking,” Wyrembeck said.

In conducting their experiment, Wyremberk and his students simulated the amount of strain that would be needed at the bottom of the cable so that it would be at its maximum tension. They used pool balls in their experiment and a force probe that could measure the tension in the cable.

“We let the pendulum bob swing down and looked at the force on the string,” he said. “We found it went up to three times the weight of the pendulum bob, then went back down.”

“It took about a year to compile the information and to conduct the experiment… I sent in all the material last summer.”

He sent in the results of his experiment last summer and was notified by officials of the NSTA this past February that he was one of the winners. The requirements for entering the competition were extensive.

He was required to submit the following to the NSTA:

  • An abstract of his physics program, including his philosophy of education. “My teaching philosophy parallels that of the great progressive educator, John Dewey, who believed students learn best through doing or experience,” Wyrembeck said.
  • A full description of his curriculum and his methodology. “I strive to create the best possible learning environment for all of my students by developing a robust curriculum that focuses on student-centered inquiry,” he explained. “My two main objectives as a physics teacher are to seek out exemplary research based, physics teaching practices that actively promote student investigations of nature and to find the resources necessary to implement those practices into my physics curriculum, on a daily basis.”
  • His resume.
  • A minimum of four letters of reference, which included a letter of nomination. Dr. John Eickholt, superintendent of the Howards Grove School District, nominated Wyremberk. He also had letters from Mark Hinterberg, principal of Howards Grove High School and from three of Wyremberk’s students: Justin Bolenstein, Ryan Jahnke and Joshua Schlegel.
  • An outline of the experiment.

“It took about a year to compile the information and to conduct the experiment,” Wyrembeck said. “I sent in all the material last summer.”

Superintendent Eickholt said he is very proud of Wyrembeck and his accomplishments. “I feel fantastic about Ed winning the award,” he said. “This is a tremendous honor for him and for the school district. Any time someone throws a project like this into the national arena and wins, we are very proud.”

Wyrembeck is an Oshkosh native who earned a bachelor of science degree at UWOshkosh and a master of arts in education degree at Marian College in Fond du Lac. He resides with his wife Theresa and their children Nicholas and Lucas.

  • Ed Wyrembeck
  • Howards Grove High School
  • Wisconsin

Featured Products

Educator Success Stories

Go to top