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Activity (Hands-On)Grades 6 - 7

Maximum Mentos Fountain

Students make sense of the energy transfer that takes place in Mentos fountains. Students play the role of engineers as they test, design and build Mentos® fountains—a dramatic example of how potential energy (stored energy) can be converted to kinetic energy (motion). They are challenged to work together as a class to optimize the design of the basic soda/candy geyser made by the teacher. To do this, three research teams each investigate how a different variable—nozzle shape, soda temperature, number of candies—affects fountain height. They devise and run experimental tests to determine the best variable values. Then they combine their results to design the highest fountain to compete head-to-head with the teacher's geyser design.

A photograph shows four Mentos geysers of different heights going off at the same time in front of a garage door. Each contains five plain Mentos drops, but different liquids. Left to right: carbonated water (Perrier), Classic Coke, Sprite and Diet Coke. Green marks on the garage door indicate 0.5 m height marks. The Diet Coke shoots the highest, then the Classic Coke, then Sprite, then carbonated water.Students build Mentos fountains

Through this activity, students gain experience with two tasks that are vital to many real world engineering projects: 1) systematically testing, evaluating and optimizing a design, and 2) collaborating with other engineers or research groups.

After this activity, students should be able to:

  • Explain the energy process that takes place in a Mentos fountain.
  • Collect and interpret experimental data.
  • Collaborate with other groups.
  • Revise a design based on test results.

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