Science Fair

22 Feb

The junior high science fair has taken over our life this week.

DJ is in 7th grade and built a trebuchet with his dad.  For those of you who don’t know what a trebuchet is, it is basically a medieval catapult used to throw rocks at castle or city walls to break them down so the army could enter.  Sometimes they were used to launch diseased carcasses into the city to get people sick – kind of like biological warfare.  DJ’s project is to test throwing a tennis ball with the trebuchet having various amounts of lead as his counterweight.  He measures the distances of the throws based on how much lead is in the bucket.  His results found that with 6 ingots he got the best results.  When he added two more ingots, the results were slightly longer/better, but the trebuchet shook and even bent some rods.  That’s the sign of wasted energy and it isn’t worth the little bit of extra distance that he achieved.  It’s a cool project.

He has been working very hard on the project since the beginning of the year.  He did all the research by himself.  He knew what size to make the beam and sling in relation to the weight of the ball.  Actually building the trebuchet was a new experience for him.  Dan had to use the power tools to cut the wood, but DJ did a lot of the nailing and tweaking of the device.  He did all the testing himself. He wrote the paper by himself.

However, we stepped in this past week to edit and critique the paper.  He’s a good writer but proof reading was definitely needed!  I took a movie of the final testing with my iPad.  He’s making an iMovie from it.  It’s good.

I spent Monday helping him with his backboard.  I’m amazed that in this day and age we still have backboard requirements.  Tell me what part of science involves cutting, gluing, construction paper, and painting?  I can see that requirement 30 years ago, but with today’s technology, don’t you think a PowerPoint presentation would be better?  I do.

The backboard is only worth 10 points out of 120 so I’m fine with helping him do that part.  After we had everything glued down, he went to school yesterday and his science teacher informed him that he had to have the safety sheet on the board.  It’s not.  There’s no room for it.  Bummer…  But apparently it can be attached to the back if necessary so the crisis was averted.  🙂

He was also informed that he can’t bring the actual trebuchet to school with him on Friday for the science fair.  It’s too big and bulky (says the science teacher).  What?  That’s the best part!  He’s been practicing his whole oral presentation by pointing to the parts of the trebuchet and telling why the beam or sling length is important, etc. Crap on a cracker!  I want him and Dan to build a mini-version in two days to bring in.  They can do it, right?  Just for demonstration purposes?

Yes – we have pictures he can refer to instead.  But it’s not the same….

I leave you with a picture of DJ firing the trebuchet this past weekend.  I got a good action shot!

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