# Introducing forces and making mazes

This term I have picked up a Year 7 Science class (mostly due to timetabling changes) and we have started the term with a ‘Bikes and Trikes’ topic, which is essentially aiming to cover levers, simple machines and forces. I had this class once, which was mostly a let’s get to know each other a bit better (we did flipgrid introductions with mixed success, but it was a good way for me to figure out the more digital literate and confident students, and the students who can follow instructions more easily than others). After this, I walked through a colleagues class, and saw their students blowing ping pong balls around using straws, and thought to myself ‘I’m poaching that’ for lesson 2. It was an easy way to introduce the ideas of the lessons, which were

1. A force is a push or a pull
2. Forces can change an objects speed and direction (or velocity…. it is yr 7) or forces can change an objects shape

We wrote some notes (still a good settling activity, especially this brand new class I had meet once) and did a think, pair, share activity on any ‘forces’ they could think of. There were lots of star wars themed answers, and a few space themed ones to. We then watched some videos of rollercoasters etc…

And then I let them lose with ping pong balls and straws, and they had a ball. I set them a challenge of getting equal and opposing forces acting on the ball, so it stayed still. This proved a bit too challenging as many students just couldn’t resist blowing a big puff to knock the balls off the center.

I then thought about getting students to design mazes that they had to get their ball to travel along. This was much more successful at getting the idea that the direction of the force, as well as the size of the force is important. And I was amazed by the effort that went into some of the groups mazes, they tried and failed, and tried again, decided things were too easy or too hard and really got into it.

The groups of students who worked more collaboratively were able to get their ping pong balls to the ends faster than others, because they positioned themselves around the maze so each person had a different direction to direct the ball.

And if I had thought about it a little more, I ought to have put some computational thinking ideas in there – how many breathes/blows to get the ball to the end, what direction does the next breath need to be etc. How could you get the ball to the end of a maze with the least breaths possible? It would have been a useful little exercise similar to how I have seen sphero’s or bee bots used to get students designing instructions/algorithms to get a sphero out of a maze.

And for when I do this next time, I will think about how I can get the idea of direction change a little more explicit in the preparation for the maze, and how I can follow up (I left it too late and it was basically an oh crap, the bell is about to go, packing up now please…… so working on timing is obviously important too)