Metallurgy

Our little sentimental trip down memory lane the other day gave me the kick I needed and now I'm back! For a while at least, no promises since I have no idea how accurate these rumours are that this year will be even hard than the last!

So I decided to try my hand at another experiment and it was at least half a success! I have to admit to only choosing this one as it was labelled as 'Metallurgy in the Kitchen' and metallurgy sounds like a pretty awesome word! Material science always seems a little more of chemistry that physics but hey with a word like metallurgy who cares?!

So I assembled my apparatus as shown here:

The tidiness is a completely naturally instinct, it totally wasn't staged for the photo... Anyway so I needed 3 unbent paperclips. I had to take two of them and heat them until they went orange like so:

And put an orange paperclip in the egg cup of cold water and the other on a plate to cool. Then I tried bending each of them.

The paperclip that had nothing done to it was very difficult to bend (left) and actually part of it snapped off, the next difficult was the paper clip in the cold water (middle) and the most flexible was the one left to cool on the plate (right).

For the first paperclip, bending it backwards and forwards created a work hardening effect leading to it snapping. It gets harder and harder to bend because the atoms in the metal have to rearrange themselves and they become closer and there is less room to bend.

The process performed on the paper clip that was left to cool on the plate is called annealing. The heating gave the atoms lots of energy so they are able to deform more and therefore is more flexible.

The final paperclip is were my results are a little off... The process is called quenching and is supposed to leave the paperclip even less flexible. Apparently this occurs because iron has two stable crystal structures so before when we cooled the paper clip slowly the atoms have time to organise properly. When they are cooled quickly by the water there is no time and they form a third structure called martensite which is hard, brittle and stiff. So maybe my paperclips didn't have enough iron in them or maybe my water wasn't cold enough? Anyway, its no fun when it's perfect!

Water Rocket

Today was the last Physics lesson ever with one of my teachers so we had a treat! We got to set off a water rocket which was really great! We had a bottle half filled with water and a foot pump which we (I say we but of course I didn't do any of the hard work!) until the pressure built up high enough for the bottle to go shooting up!

At first the lid was screwed on too tightly and the rocket shot off at an angle... Then it was tied on too tightly and wouldn't shoot off at all... And then we had the most perfect brilliant one just as we were about to give up! it went straight up in the air and I felt about 6 years old (in a good way)! So I'm counting this as a success experiment!

Cans of Density

I have been interested to see if this experiment would work for a while but no one in my house drinks coke, actually we hardly ever drink fizz but on Friday I had a group of friends over to watch the Royal Wedding (it was sooooo lovely!) and we stocked up! I needed a can of diet coke and a can of normal coke, I bought both so it was the perfect opportunity!! Except I was so busy hanging bunting and licking the bowl after my Dad iced the cupcakes cleaning that I forgot about the experiment and my friends drank all the normal coke! So I made a few alterations to the experiment...
The theory is that a can of fizzy drink that has more sugar in it will sink because it is more dense than the water and one without sugar will float. This did actually happen! The diet coke apparently has no sugar so it floated and the can of Aranciata had 30.9g of sugar so it sank!

So the experiment worked which is actually just really lucky because this wasn't exactly a fair test. There is a whole list of different ingredients and the cans themselves could weigh differently but  the difference in flotation ability is remarkable different so I'm counting it was a total success?

Mateaser Meteors

This was a really nice experiment because I was free to play without too much fear of it going wrong! Here is a video of what happened (my video skills are improving slowly - yes, I laugh way too much but you can't hear what my Dad is doing in the background!)

The Earths suface is demonstrated by the cocoa powder and the flour underneath are the inner layers of the Earth.

Each of the 'meteors' did create pretty impressive craters but it is interesting to see the patterns of displacement from the meteors that came in from different angles

When the 'meteor' hit the ground straight down it displaced the top layer quite uniformly. The others clearly have exposed more of the lower layers layers in a particular direction.

Speed of Light experiment - Take 2

I went to my grandparents house yesterday and had a second attempt at the speed of light experiment!

This time I used marshmallows, which despite it's yumminess factor it wasn't the easiest of experimental materials as demonstrated by these pictures of the clear up - I'm not going to lie, the messier it is, the more fun it is!

However I have to admit to turning my back on this philosophy when the marshmallows were in the microwave. They don't just melt as I expected, they actually expanded! In places growing to at least three times their size! I had visions of myself spending hours cleaning the sticky remnants of an exploded marshmallow from the inside of my grandparents microwave so fought the curiosity of answering the question 'woa, do marshmallows explode in a microwave?'! I googled, apparently there is a limit to how large they can get and don't explode..

I took out the turning plate and put it in upside down over the rotating parts. In a microwave oven, microwaves are produced and are then reflected by the sides of the microwave oven creating a standing wave. The amplitudes of the two waves will add, creating spaces where the microwaves are twice as strong and places where there are none (As shown in the picture. The centre of the wave is where there is zero amplitude) Therefore when I measured the distance between two of the most melted spaces to be 0.066m, I am finding the distance between two peaks (including the bottom peaks) so to find the wavelegnth I must multiply the distance by two.

I found on wikipedia that the average frequency of a microwave to be 2.4 GHz which is the same as 2.4 x 1,000,000,000 Hz.

Speed of light = Frequency x Wavelegnth

Speed of light = (2.4 x 1,000,000,000) x (0.066 x 2)

Speed of light = 316,800,000 m/s

Which is actually pretty close all things considered! Only 17, 007, 542 m/s away...

The final lesson learnt from this experiment? You can eat too much marshmallow...

Electric Custard

So this morning I failed at making a hovercraft from a 'It's Chico Time' CD and some card... Turns out that CD really is totally useless!

So to make myself feel better I made a tasty snack of - ELECTRIC SLIME! Actually I'm not totally kidding about the 'tasty snack' part - I lasted about half an hour before my curiosity got the better of me and I tasted a tinsy bit of it... It wasn't tasty.. At all!

Electric slime is made out of cornflour and vegetable oil which is mixed together until it is the same consistency as cream. Apparently you are also supposed to spill cornflour all over the work top, or maybe that's just me?

Rub a balloon until it is charged. It becomes positively charged because you have knocked some of the negative electrons out. Then bring a spoonful of delicious dripping slime close to the balloon. It's consistency will thicken and it will be pulled towards the balloon. This is because the slime is made of cornflour which has lots of particles. The particles are coated with an insulating liquid so the charge can't leave the particle so instead the charges are just pulled more to one end. The positive end of one particle will attract the negative end of another particle. This makes the slime more attracted to itself and therefore thickens. The slime is also attracted to the positive balloon.

In the picture above there is some slime in the cup which was also attracted to the balloon - it looks like it has climbed out of the cup!! Unfortunately it wasn't quite as awesome as that!

My lovely mum volunteered as my glamorous assistant and helped me to video the experiment. Its no work of art and I still have no idea why I was whispering but it kind of shows what happened! 

Actually, now I think about it this is actually quite a good practical for demonstrating induced dipoles for Chemistry!

Hot Air Balloon

I pretty much knew how hot air balloons work before this experiment but it's something I've always wanted to try (a miniature version and a ride in a real one!) so I decided to do it any way!

You need a thin plastic bag, some cardboard and a toaster. My parents insisted on supervising on the grounds that 'toasters are dangerous' or rather 'me and toasters together are dangerous' but secretly I think they just wanted to see it! You roll the cardboard into a tube that is longer than the bag. I think my tube could have done with being a bit wider so more air was funneled into the bag but I was limited by cardboard supplies and it still worked okay. Put the bag on the tube and that on the toaster. Then turn the toaster on!

It worked! After a painful wait (I had a crowd watching, well 3 members of my family, and I was so worried it wouldn't work!) the bag started to fill up with air and then rise up off the tube. But once the whole bag was off the tube the bag fell which was slightly disappointing but I'm still counting it as a success and to improve I would suggest a wider tube.

And then I tried again which on reflection was pushing my luck a little but in my defense I thought a warmer bag might go higher. What actually happens is the bag starts to melt!! So my Physics experiment became a Chemistry lesson because of course I was using a thermosoftening plastic which means it doesn't retain its shape on heating...

Anyway, back to the Physics - the bag lifts up because the toaster heats the air inside the bag (as my tube wasn't wide enough it also heated the air outside the tube a little so this supports my theory that this had an affect on the experiment) causing the air to expand slightly. This means that less air can fit inside the bag and some will come out making the bag lighter and less dense so the bag floats above the heavier air.

Jet Powered Hot Guys

Today I built a jet powered rotor and it worked!! Yay me :) Or rather Yay Physics but I like to think it was my expertise that was the major factor in this success! I'm just kidding it was beautifully simple!

You will need two straws (I had pink and green) and some scissors. You cut one straw (the pink straw) so it is the same length each side of the bendy bit. Then you fold the end of the short side other straw (the green straw) in half lengthways so that you can squish it inside one end  of the short pink straw. Now you bend the long green straw downwards and the short pink straw sidewards, put the long green straw in you mouth (don't hold it too tight) and blow! It will probably spin out of your mouth at this point but with a bit of practise you'll get better control! If you suck, nothing happens...

This is because when you blow you push air out with a momentum which pushes the straw round. When you suck you pull air in from all different directions and because momentum has a direction the different directions will cancel out and there will be zero momentum to push the straw.