Engineering challenges have been a long time staple of my science courses. I have run numerous challenges after the school day, and manage to weave a few into the school day too. I take the time to run engineering challenges because the act engages students in way that harnesses their creativity, ingenuity, problem solving, and ability to create. The students also face failure in a safe way, and work collaboratively with others to overcome the problems of the moment. I believe these are all essential skills in today's technology driven world. I love the fact that education is transitioning to embrace engineering challenges as part of the curriculum. The recent STEM or STEAM movement has been moving engineering style activities into the spotlight and into the classroom. I believe classes will be better for it.
In this blog I will outline a few of the engineering challenges I do with my students.
I like to run this challenge early in the year when the students haven't had much Physics yet. This way the project serves as engaging introduction to the first half of the course content. I provide the students with a paper towel tubes, popsicle sticks, rubber bands, hot glue and some other common office supplies. There goal is to build a catapult capable throwing a ping pong ball proficiently in four different challenges: distance, height, accuracy, and reliability. Distance is about how far the ball can be launched. Height is how many steps up a stair case the ball can reach. Accuracy is about how far away can the catapult still reach a 1 meter diameter circle. Reliability is how many shots out of 10 can the catapult land in a box from a distance of 1-2 meters away.
Depending on my mood some years I have Physics students engineer an egg drop or an egg catch device. The egg drop requires students to use copy paper and masking tape to protect a raw egg when dropped from a height of 8 meters. If the mass of the empty device is between 35-70 grams then there is no penalty nor a bonus. Devices that mass over 70 grams are penalized for excessive materials. Devices under 35 grams receive bonus points the lower they get. A problem presented to the students is that the device is more likely to work with more materials for protection, and less likely to work with less materials. The engineering challenge lies in understanding how to use the physics concepts to protect the egg with less materials. The concepts of work, potential energy, kinetic energy, momentum and impulse are taught before this challenge. My best students have managed to get a working device at a 5 gram mass of paper and tape. For reference a piece of paper is 4 grams.
The egg catch is the reverse engineering challenge. The students are challenge to build a device out of any materials they like to safely catch a raw egg dropped from a height of their choosing from 1-5 meters. Their goal is to protect the egg and reach a good score. The score is calculated by taking drop height in centimeters and dividing by volume of egg catch device in decimeters cubed. So the greater the volume the less they score and the greater the height the more they score. In either egg event the goal is to think through a solid physics solution, to make it real, and to re-engineer as needed.
Green Cars is a project based learning challenge for my 8th graders in May after the April PSSA. The first part of the challenge is to research a car that gets greater than 40 MPG or MPGE. The students follow a rubric to create a Google Slide presentation for their green car. The second part of the challenge is to build a Green Balloon Car. I define a balloon car as being "green" if it only moves due to exhale of a balloon and it travels at least 5 meters down the hallway. I provide basic materials such as lids, wooded skewers, straws, hot glue and the balloon. The students must find the body materials from recycled materials such as cardboard, juice boxes, and plastic. This task challenges the students as they soon learn that weight, balance, and friction must all be working in harmony to reach the goal. The picture you see below is car that met the goal. Please note it took the student team three prototypes and about six revisions to finalize this design.
Race 2 Achieve
R2A is a project based learning challenge I created for Physics. When we are studying kinematic motion the students are introduced to R2A. The first task is to create mousetrap powered car exactly according to the directions in the kit. In this way all student teams should create mousetrap car clones. Then they run cars and record kinematic data. Lastly the whole class discuss how the cars performance were the same or different, and why. The project is then put on hold until the forces unit.
In the forces unit the students learn about torque and moment arms. The teams return to R2A to modify the length of their mousetrap arms and test subsequent impact on performance. Then in the next unit the students learn about friction. The teams then test out numerous tire materials on three road surfaces: carpet, wax paper, and saran wrap. In this investigation they are trying to determine the most effect tire material for each of the road surfaces. Then in the next unit the students learn about work and energy. The teams then study the efficiency of the mousetrap cars as they test different size tires, tire materials, and and mousetrap arm-lengths.
Lastly after four R2A investigations, four units in Physics, and four months in time the students are now ready to put together all the data collected to develop a strategy for Race Day. Race Day is a four leg mousetrap car race in the style of a NASCAR race. In the first leg, they must launch the mousetrap car from rest and have it accurately travel 9 meters along a 1 meter wide wax paper road. The car is required to stop on its own inside of a 2 meter long carpeted pit-stop. Leg 2 requires the car to travel 9 meters down a saran wrap road as fast as possible with no need to stop. Then leg 3 requires the car to travel from rest over 9 meters of saran wrap and to stop in a carpeted 2 meter long pit stop. Lastly, the cars need to travel 9 meters over wax paper as fast as they can with no need to stop. The student have three minutes at each pit stop to change wheels, change tires, make repairs and wind the car for the next run. Times are recorded for each run of the race and penalty seconds are added for not making the distance, leaving the sides of the track, or for taking longer than three minutes in the pit-stop. The top cars can complete the entire race in about 32-35 seconds of run time.
TARC is a national Rocketry Challenge that involves building a rocket capable of carrying a raw egg to a defined height, and returning the egg safely in the rocket to the ground in a defined amount of time. This is a challenge that I open up to 10 students in grades 6-12. We meet after school once a week for 2.5 hours, and meet on Saturdays as needed to practice launch. I do my best to run Rocket Team on the same schedule as a fall sport, but there are some years where must continue to launch and re-engineer all winter long.
This years challenge is to build a model of the Saturn V rocket and have it carry three raw eggs to a height of 850 feet and return the eggs safely in a time of 40-44 seconds. This will be hard year for sure as the rocket must carry a lot of egg weight.
This an intermediate unit challenge I run with interested 8th graders. We meet after school for 2.5 hours for about 1 month in the winter to prepare for this challenge. The requirements change each year. Last year was to make the tallest tower that could support the most mass for the least cost. The tower had to be efficient with its pieces as there was cost to each piece. They also are required to create a blueprint of their design, keep a journal the design progress, prepare a budget, and make a five minute presentation and demonstration of their design. In the picture below our team took 1st place with a 1.4 meter tower that held 17 physics textbooks, and a stool for a mass of 38 kilograms.
Science Fair
I run the science fair team at Greenwood. We participate in the Capitol Area Science and Engineering Fair (CASEF), and the Pennsylvania Junior Academy of Sciences (PJAS), fairs. I mentor students from grades 7-12 in a before/after school as needed setting. In the Photo below 7th grade student Alan Everett created a home made radon detector for $35 where the commercial detectors cost $250. In his testing he found radon levels over the safe range in his grandparents house and in his piano teacher's house. He was also able to show three other homes that they had no radon problems in their basements. Alan's project went on to win 1st Place in the Engineering category at both PJAS and CASEF and again at PA state science fair.
Over the years have had so many memorable experiences with students in various engineering challenges. When students come back to see me after graduation, the engineer challenges are always brought up as a memorable experience. I truly believe impact and long term impression is made through the challenge, the thinking, the re-engineering and the struggles that are always a part of engineering challenges.
Please comment below if you have any interesting engineering challenges to share, or if you have questions regarding the content I posted in this blog.
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