Crash test eggies

We were at the end of the forces topic and i was looking for a single lesson to do some momentum consolidation before moving onto the next topic. I started thinking about an egg drop type experiment to get across the idea of Force = rate of change of momentum but instead was passed a great idea to do crash tests with an egg sitting in a seat on and old trolley car. The kids were given a car with a single eggbox as a seat and they had to protect it as i rolled the cars down a 45 degree 2m long slope into a brick wall. Below are a couple of the brilliant crumplezones that the kids made i especially like the one that has a sail to presumably reduce the momentum in the first place - thinking outside the box.  One group even had air bags ( crumpled up paper protecting the egg.) It helps if you have rotten eggs as there is a real need then to protect them - one group saved all the eggs, one group were perhaps feeling a little bit more like destruction as they had no seat belts for poor mr egg who proceeded to fly into the wall or even worst in one crash he got stuck between the crumple zone and the wall.. Poor Mr egg!

Weird equipment

Clearing out the labs we found these. Any idea what it is? It says Eureka on it and the three holes in the top are different sizes. We thought some sort of heat capacity type experiment or effects of surface area on rate of reaction but the Internet has not helped me find a definitive solution yet. It looks like the aliens from war of the worlds.

Help Appreciated in comments section.

Speed of sound

I showed this to the kids the other day when trying to find clips to reinforce the idea of speed of sound vs speed of light. The kids got the idea pretty clearly and we followed it with a few measurements of the speed of sound using echos off the school building across the rugby field.  I think its good as an intro as its pretty dramatic and not a subtle observation. The experiment is great as the kids love getting within only 50 m/s of the true value just from a few stop clocks and wooden blocks smacked together.

Nuclear testing.

This video was brought to my attention and i thought it was an interesting piece of background when consider nuclear weapons, possibly in a scientific but with a historical context. I might put it on in the background whilst discussing nuclear fission in class next time and see what if any impact it has on their views.

How science doesn't work.

 I hate bad surveys. a recent  survey about mobile phone use came up with the conclusion that mobiles cause brain cancer. Looking at it in very little detail  reveals that the survey has 4 classes.


1 .Probably Carcinogenic
2. Possibly Carcinogenic
3. Not Classifiable
4.
5.Probably not Carcinogenic

This sort of survey annoys me.. what about Possibly not Carcinogenic - you can't have a survey without a sit on the fence option and if you do - you have to have a balance either side. So if this survey was conducted sensibly would we know: are we borderline thinking Probably or borderline possibly (as there is a none existent number 4). GRRRRR!!!

http://www.bbc.co.uk/news/health-13608444