Physics Day is a go! We will be showing off all our physic experiments on March 31st in the school gym. As far as we know right now, we will not be using the air track. Right now, our line up looks like:
Everything labeled Class Experiment, is pretty self explanatory. It's whatever a group has already done in class, and will be presented on Physics Day. All of the interactive presentations are something we've picked out for the younger kids to do and be a part of. Yes, keep in minds that this is for younger kids, so nothing is going to get SUPER complicated.
So, yeah. We're set for March 31st, and that's our line up. Voilà!
The balloon thing is over! I don't know why, but everything we tried failed. Maybe it was materials, a patience issue, or just bad luck, but our balloons never lifted off the ground. So now we're moving on.
We've decided that this Physics class should do something that is more geared towards the community. So, we've decided to do a sort of Physics science fair for younger kids. We've thrown out a BUNCH of ideas out there, and so far we've worked out an experiment with an air track to show elastic and inelastic collisions.
Le Air Track
An elastic collision is essentially a collision between two bodies. The total kinetic energy of those two bodies is equal before and after the collision, which means that they follow the law of conservation of momentum. Here is an example of an elastic collision, thank you Wikipedia.
An inelastic collision is when kinetic energy isn't conserved. Inelastic collisions don't conserve kinetic energy, but they too follow the law of conservation of momentum. Here is an example of an inelastic collision, thank you Wikipedia.
This will hopefully be the first of many experiments that will all be put together for a science fair!
So, the team and I are officially, and without a doubt, stuck. We have tried various launches and still we have no lift. So far we've tried different designs of balloons and even free hand made balloons. However, none of them seem to want to lift off. Of course, with our various flight tests we have changed some more things around yet again!
We are not using a can engine anymore. We're trying to use a cotton ball dipped in rubbing alcohol as fuel. We're still not completely sold on this new idea, so we're thinking of using both or going back and forth between the two.
We're also trying to place the fuel/engine higher up into the balloon. Hopefully by doing this the hot air will be more focused on the top of the balloon right away.
We're also trying to seal the bottom of the balloon or at least make the hole smaller in size. That way the hot air can't escape through the bottom of the balloon.
And. . . That's it! We really don't know what to do. We've considered turning this balloon project into a flame thrower project, but I guess that's "too dangerous" or something. Our last hope is to go back to the beginning. We're thinking of using the same design as our first balloon, but with all the modifications we've worked out. We're thinking that the full scale model will actually work, versus our scaled down model of the same balloon. Hopefully it works, but we need materials and time to get those materials first. We'll get it done by Christmas though, I hope.
It still doesn't work!!!!
Guess what did it in this time? THE WIND!!! The top of balloon keeps getting filled with warm air, but the balloon still refuses to take off. So yes, we failed, and we are a bit stuck. After having three balloons go up in flames, we're a little discouraged. Luckily it's almost Thanksgiving, so we'll get a break to collect ourselves and try this all again. We now know what we're planning on doing next. We're just too lazy to do it on a two day week. So, I'm blogging.
So that was our latest attempt at lighting a balloon on fire! Guess what! It was a success! However, someday we will succeed at making a hot air balloon lift off from the ground! This however, will call for some desperate and extreme measures. Here is the new plan:
Find a way to launch inside, as it is always too windy to do it outside. We are thinking about trying to do a launch in the school's shop room.
We are going to try and make a different design balloon. We're trying to look it up new designs, but we're thinking about something like a Chinese lantern.
We shall see how this goes after break! Happy Thanksgiving!
So I just wanted to do a quick update on the new balloon! Here is is in all its wonderful glory!
Me with the 3rd balloon prototype.
It is completely done, and is just waiting for a calm day to set off. You can see that we actually changed engines again. Instead of using two normal cans, we are using one large Arizona Tea can. The can is just a few grams heavier, but it is more stable, and there is no way that it will fall apart. You can also see the larger and stronger wire that we have used to fasten it to the balloon. Don't worry the thick wire was only used there. We used the lighter and thinner wire to line the balloon in order to give it a bit more structure.
This is our new can. Thank you Steven!
So there you have it. Hopefully this will be the one to actually lift off! If not, I'll be uploading another video of students setting things on fire to YouTube.
So yes! We have done a lot of stuff recently! Allow me to fill you in.
We finished making two more balloons. With our second balloon we changed a few things. We braced the engine wire, raised the fuel punctures in the engine, and we glued the cans of the engine together.
Amber with our second balloon.
With our first flight, nothing really happened. The top of the balloon was very warm but would not lift from the ground. However, the glue completely melted on the cans, so they fell apart. Since the balloon didn't go up in flames, we decided to take it inside and fix it up. So while we were inside, we changed the engine design. Instead of using three cans, we shortened it down to two.
We went from this, a three can engine (one of the cans is missing)
To this, a two can engine, with the top not cut off
First test flight of the day.
With our second test flight, we still didn't get lift off. However, we had a problem. By the time we were ready for our second flight of the day, the wind had picked up a bit. This threw our entire test flight off. We tried to hold the balloon before the balloon lifted, but the wind blew one of the sides toward the center, and it caught on fire.
Second test flight of the day.
Good news! We, once again, learned A LOT from these test flights. Thank you for prototypes. So for our third balloon we will be trying some different things. First we will be structuring the inside of the balloon with wire. This way the balloon does have more structure and won't be too affected by any stray wind. We are also going to keep our new engine design of only two cans. Along with that, we are not going to cut the off of the first can. This makes it so that there is a smaller and more focused hole for the burning fuel to come through into the balloon. Finally, we will only launch on a good day. That means little to no wind! That's why I'm here now. It's windy and I need to update this blog. So there you are. Cross your fingers for a good launch day tomorrow.
I am sick and tired of writing this, so if the internet dies and I lose this post again, you are never ever going to see it. Ok, on to the actual project.
We finished the balloon! We were also able to take our wonderful prototype air balloon and test it! Though it did end up getting set on fire. It was awesome by the way! So though this wasn't a successful launch per say, we did learn a lot about this launch.
We need to make sure the engine is further into the balloon.
We need to hold the balloon steady until the balloon properly launches.
We should try to launch on a still, no so windy day, if at all possible.
And we need to make sure that our holes are not so low on the can, so we can put a proper amount of rubbing alcohol in the engine.
So! This is why people should prototype. With this launch, we are fairly confident that our new balloons will launch like they need to. We will be making two balloons this next time, so it may take a while before we do a new launch. We're doing this so that we can change the construction of one of the balloons to see if it makes any difference. It also means that we have a backup balloon if the next one goes up in flames like our last one! So there you are, balloon flight test number one!
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