Beebe School Engineering: February 2006

Fix a broken femur challenge

This fantastic challenge was developed and implemented by Jarred, also of the GK12 program. Visit his website to learn more about the implementation and to see details of the artificial leg construction. His activity deals with numerous biology, chemistry, physics, medicine, and engineering sub-topics. From his blog:

Activity Progression... (suggested)

The activities described by this blog are presented in semi-random order. Educators will find that a fun and effective engineering warm-up can be had by presenting any of the following challenges to the students:

Masking tape bridge
The ubiquitous "tallest paper tower" challenge, one incarnation of which is found here
Potato chip protector structure

After introducing the concept of engineering design, I have found it beneficial to discuss engineering sketching, as it is the manner in which engineers communicate. The engineering sketching introduction activity can be found here:

Introduction to engineering sketching

Finally, the remaining activities are intended to supplement the science concepts covered in the classroom rather than to replace them. Very few jurisdictions have engineering learning standards at the k-12 level. These activities are to run in parallel with discussions of the fundamentals in science class.

Temperature and Chemical Reaction Rate Activity

Grade level: 7
Time required: 4 class periods
Cost: high. Used donated LEGO Robolab kits (x10) to measure and log light data from the glo-sticks.
MA frameworks: Physical science 13, 14, 15, 16.

This activity uses LEGO Robolab Investigator to explore the relationship between temperature and reaction rate (or intensity, as we are referring to it). Students observe the light emitted from glo-sticks placed at different temperatures and interpret the results using Microsoft Excel charts. Connections with math and computers are explored explicitly. Issues of chemical kinetics (at a conceptual level), thermal conduction, and data investigation, along with some exploration of Robolab programming are explored.

Modeling Conservative Substance Transport in Water Systems

Grade level: 8
Time required: 4 class periods
Cost: $25 for a water pump and misc hoses
MA frameworks: Physical science 4, 8.

This activity investigates the movement of conservative species such as dye or Chloride (Cl-) in moving water systems. Students set up a laboratory experiment and gather data. They then model the system using mass balance equations and compare the results in Excel. The data gathering segement uses LEGO Robolab Investigator. Overall use of this information allows them to discuss the movement of salt in a local waterbody. How long does it take to leave after being applied during a winter storm? How long would fish have to deal with it in their environment?

Link here for the Modeling Conservative Substances Worksheet. Description of Euler's Method, the numerical method used to solve the salt mass balance equation (which is, in truth, a differential equation).

d[salt]/dt = -(Qout/V)*[salt], where Qout is the flow rate, V is the volume of the beaker (up to the top), and [salt] is the salt concentration. NOTE: seawater is approximately 15 g/L salt (15 ppt).

Solar Still Design Challenge

Grade level: 8
Time required: 5-7 class periods
Cost: $0 with recycled materials
MA frameworks: Physical science 4, 8, 9, 10, 15.

This activity challenges students to design and construct a solar still. The still's purpose is to remove salts from water, rendering the water drinkable. The design challenge builds upon understandings of solar energy and design gained by students who have completed the Solar Cooker Challenge. Issues of solar energy, design, engineering sketching, and phase changes in different chemical compounds (water and salt) are addressed.

Link here for Solar Still Challenge sheet.

Link here for an interesting story about the use of solar stills.