Students learn about the role engineers and mathematicians play in developing the perfect bungee cord length by simulating and experimenting with bungee jumping using washers and rubber bands. Working as if they are engineers for a (hypothetical) amusement park, students are challenged to develop a show-stopping bungee jumping ride that is safe. To do this, they must find the maximum length of the bungee cord that permits jumpers (such as brave Washy!) to get as close to the ground as possible without going "splat"! This requires them to learn about force and displacement and run an experiment. Student teams collect and plot displacement data and calculate the slope, linear equation of the line of best fit and spring constant using Hooke's law. Students make hypotheses, interpret scatter plots looking for correlations, and consider possible sources of error. An activity worksheet, pre/post quizzes and a PowerPoint® presentation are included.

Students are introduced to servos and the flex sensor as they create simple, one-jointed, finger robots controlled by Arduino. Servos are motors with feedback and are extensively used in industrial and consumer applications—from large industrial car-manufacturing robots that use servos to hold heavy metal and precisely weld components together, to prosthetic hands that rely on servos to provide fine motor control. Students use Arduino microcontrollers and flex sensors to read finger flexes, which they process to send angle information to the servos. Students create working circuits; use the constrain, map and smoothing commands; learn what is meant by library and abstraction in a coding context; and may even combine team finger designs to create a complete prosthetic hand of bendable fingers.

Find the current due to closing a switch using equivalent resistance and Ohm's law.

How to calculate the current through a resistor in parallel using equivalent resistance and Ohm's law.

Students perform DNA forensics using food coloring to enhance their understanding of DNA fingerprinting, restriction enzymes, genotyping and DNA gel electrophoresis. They place small drops of different food coloring ("water-based paint") on strips of filter paper and then place one paper strip end in water. As water travels along the paper strips, students observe the pigments that compose the paint decompose into their color components. This is an example of the chromatography concept applied to DNA forensics, with the pigments in the paint that define the color being analogous to DNA fragments of different lengths.

In this video, David explains how Louis De Broglie got his Nobel Prize for the idea of matter having a wavelength.

David defines the terms amplitude and period for simple harmonic motion and shows how to find them on a graph. Created by David SantoPietro.

In this first part of a two-part lab activity, students use triple balance beams and graduated cylinders to take measurements and calculate the densities of several common, irregularly shaped objects with the purpose to resolve confusion about mass and density. After this activity, conduct the associated Density Column Lab - Part 2 activity before presenting the associated Density & Miscibility lesson for discussion about concepts that explain what students have observed.

Concluding a two-part lab activity, students use triple balance beams and graduated cylinders to take measurements and calculate densities of several household liquids and compare them to the densities of irregularly shaped objects (as determined in Part 1). Then they create density columns with the three liquids and four solid items to test their calculations and predictions of the different densities. Once their density columns are complete, students determine the effect of adding detergent to the columns. After this activity, present the associated Density & Miscibility lesson for a discussion about why the column layers do not mix.

In this video David derives the mirror equation and magnification equation. Created by David SantoPietro.

Deriving formula for centripetal acceleration in terms of angular velocity. using linear speed formula.

Students design and create their own nano-polymer smartphone or tablet case. Students choose their design, mix their nano-polymer (based in silicone) with starch and add coloring of their choice. While thinking critically about their design, students embed strings in the nano-polymer to optimize both case strength and flexibility. Students may apply strings in a variety of ways in order to maximize their individual design’s potential. Determining the best mixing ratio is also key for success in this challenge.

Students find and calculate the angle that light is transmitted through a holographic diffraction grating using trigonometry. After finding this angle, student teams design and build their own spectrographs, researching and designing a ground- or space-based mission using their creation. At project end, teams present their findings to the class, as if they were making an engineering conference presentation. Student must have completed the associated Building a Fancy Spectrograph activity before attempting this activity.

Students use two different methods to determine the densities of a variety of materials and objects. The first method involves direct measurement of the volumes of objects that have simple geometric shapes. The second is the water displacement method, used to determine the volumes of irregularly shaped objects. After the densities are determined, students create x-y scatter graphs of mass versus volume, which reveal that objects with densities less than water (floaters) lie above the graph's diagonal (representing the density of water), and those with densities greater than water (sinkers) lie below the diagonal.

In this optics activity, demonstrate diffraction using a candle or a small bright flashlight bulb and a slide made with two pencils. Learners will observe the diffraction pattern and learn that light has wavelike properties.

What happens when there's way more than two holes? Created by David SantoPietro.

With a simple demonstration activity, students are introduced to the concept of friction as a force that impedes motion when two surfaces are in contact. Then, in the Associated Activity (Sliding and Stuttering), they work in teams to use a spring scale to drag an object such as a ceramic coffee cup along a table top or the floor. The spring scale allows them to measure the frictional force that exists between the moving cup and the surface it slides on. By modifying the bottom surface of the cup, students can find out what kinds of surfaces generate more or less friction. They also discover that both static and kinetic friction are involved when an object initially at rest is caused to slide across a surface.