Roller Coaster Mania!!

This week, we hit a big milestone. We completed our first longish challenge. The students stayed on one task, over 4 sessions, and managed to pull it off successfully! My initial misgivings on whether there would be continuity in the work, and sustained interest from the students, were all put to rest. Not only did my students stay focused throughout, they actually got quite attached to their teams and designs. The pride and ownership they felt, were very evident.

Their task was to design and build a roller coaster frame for a marble. Much in the same way as a real roller coaster, that has no engines to pull the cars, this roller coaster would also have to move on its own. Implying, that without any initial push or force, the marble would start to roll, and continue to roll, through the entire course. And just like how in real life, a roller coaster ride comes to a safe halt, the marble would have to fall into a cup in a controlled fashion.

When I first saw this challenge at Maker Fest, 2017 in Chennai. It immediately lit a spark inside me. This activity by itself, had the potential to teach my students so much. It could get them to think about energy, and how it is the reason for all motion around us. It could help them first hand experience the power of friction, and thereby get them to think of ways to minimise it. It could expose them to the challenges associated with making stable standing structures. It could test their ability to work with different materials to meet structural requirements. Best of all, it could unwittingly get them to flow through the engineering design cycle of

Ask -> Imagine -> Plan -> Create -> Improve

I knew right away, that I wanted to give this a try!

So I gathered my materials, and put together the design constraints. The primary goal would be to build a complete roller coaster, wherein the marble would make its way through the course without an initial push, and end up in a cup. Understandably, a longer run, a more winding course, hills & loops, innovative material use, and an overall cooler look, would all yield higher scores for the design. To achieve this, teams would be given a bag of assorted materials comprising straws, skewers, cardboard rolls, flat cardboard, paper plates, chart paper, thermocol base, masking tape, fevicol, cutter, marbles, and a paper cup.

We started off with a little discussion on how roller coasters worked. A few students were quick to point out that almost always, these rides start off with a big climb. Soon there were more students pitching in about how they had seen and felt chains and motors pulling the cars up. With a little more prodding they realised that there were no engines that moved the cars! So the big question then became – how really do roller coasters move? Students slowly started piecing together facts, they thought about the big climb, and how that would result in lots of potential energy. They thought about how just like sitting on top of a giant slide, when the roller coaster reached the top of the hill, gravity would pull it down, causing it to move and speed up. They thought about how a speeding object would be able to go around turns, and over hills and loops in its path. They also imagined the wind in their face, and realised how friction and air resistance would eventually slow down the roller coaster, before real brakes brought it to a halt.

Our teams were sizeable this time, comprising around 5-6 students. Numbers like these could result in one of two scenarios

  • It could end up in a “too many cooks spoil the broth” sort of situation (or)
  • It could lead to one or two students stepping up and making the challenge their own, while the rest of the team simply played along.

To avoid either of these situations, and to make the division of work easier for the students, I decided to create different roles within the team. We would have the shoes of a designer, supply manager, recorder, and project manager to fill, in each group. Through amicable negotiations, the teams have to arrive at roles for each of its members. Each roles would mean a specific set of responsibilities. This way, not only would a student be able to play to his or her strengths, but does it, feeling a sense of purpose, and pride in his contribution towards the challenge. This, to me, not only was spelling better work allocation, but also meant more hands kept out of trouble. 🙂

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So, I handed out the challenge sheet, the scoring criteria, the materials, and the role badges, so that the teams were good to go.

As always, we started off with the teams’ brainstorming and ideating sessions. Though I had allocated a good 30 minutes for this phase, most teams were very eager to get soil their hands, and start to build. When I noticed design drawings where the course started off with an upward hill, or a flat track, I realised the students were completely missing the point of the marble having to move on its own, so I decided to let them figure it out by jumping right in on the making phase.

The making phase spanned over a good two and a half sessions, roughly about 4 hours. Most teams worked together cohesively, with almost every member being involved, offering suggestions, and pitching in on the build.

I had heard time and again that given a problem, every mind, or set of minds would be able to produce a different solution for it. True to that, each team’s roller coaster progressed in such different ways! There was a big variety in the design itself. We had giant slides, and tunnels, and 360degree turns, and hills and even one loop! While some teams expanded vertically and stayed within the size of their thermocol base, others cut up their thermocol bases and spread out horizontally. There were so many differences in the way the materials were used too! While one team used the cardboard rolls as tunnels, another used them as columns for supporting their structure. While some groups were struggling to make turns using straws, others used the paper plates to create smooth circular turns in their course.

A couple of things really stood out for me. First, the ease with which students were able to pick up their work at the start of every session, right from where they had left. That was truly amazing. This work continuity, had been one of my biggest initial concerns, so I was thrilled with the way things had turned out. Another exciting thing to watch was the minute to minute problem solving going on in every team. Students would try something, realise it didn’t work, then talk, watch other teams, try something different, and keep at it till it worked, only to find soon enough, that something else didn’t work. 🙂

One particular team spent an entire session fixing problems, only to realise that the best solution would be to tear their design down and restart! They actually went ahead and did just that, kicking failure right in its face, and ending up with a much better design!

Here’s a short video showing the teams working on the challenge.

In the building excitement, I must admit that the roles sort of took a backseat. This thankfully didn’t mean that nobody did anything, rather everybody did everything! I decided to let the students work the way that felt natural to them, and did not stress much on the forgotten roles and responsibilities. I made a mental note however, to focus on this, another day, for another challenge.

Soon time came, to test their designs. I was ready with a scoring chart that listed out the various criteria on which their designs would be judged.Untitled

The most important design requirement was that the roller coaster be complete, implying that the marble needed to start rolling, stay on course, and fall into a cup. If in 3 out of 5 turns, the marble managed to do this, the design would be considered a success. Only a successful design, would qualify to be scored on its other design complexities like length, turns, and loops.  I also wanted to bring in an element of peer judging, so I let the last criterion innovation in design and material use, a.k.a the coolest design be scored based on a class wide vote. While most of the teams managed a successful show, a couple of teams could not keep their marble on track, automatically losing the chance to compete. However, it was a true show of sportsmanship when one of these disqualified teams actually won the maximum votes for the coolest design.

We reflected on the activity, using the star & wish strategy, in a peer assessment format. Each team, wrote out for every other team, one star – a point of praise or appreciation, or a mention of something that was done really well, and one wish – a suggestion for improvement.

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