Tuesday, 8 April 2008

Rising heat, bubbles and juice

What a wonderful day we have had today. No television, no tears, no tantrums. We all made it out of our pyjamas. We all had our hair brushed. We all had lots of fun. Success *grin*. Here are the highlights.

This morning we asked, 'why do hot air balloons fly?' We watched this youtube clip for clues.

We noted that when the blow torch was in action the balloon inflated and headed upwards.

I switched the oven on it's very coolest setting and after a short while we felt inside. The top part of the oven was very warm whereas the bottom was just say warm. What we suspected about hot air rising was true. The hot air in our oven rises to the top too. Note that this doesn't work with the oven on fan setting as I found out when I was thinking about this last night.

So, hot air rises but what about hot water? We took two small and identical glass jars. We filled one with hot tap water and one with cold water. We added some food colouring to the hot jar and placed a card on top of the cold jar. When we had a suction with the card we tipped the cold jar up and placed it on top of the hot jar. I slowly pulled out the card and we watched what happened. The hot coloured water and the cold clear water mixed. Was this because the hot water was trying to rise to the top or was it because the two jars of water would just mix together no matter what?

We repeated the experiment with the hot coloured water on top.

Here are the jars balancing precariously with the card still between.

After carefully removing the card the colours remained separate. When the hot water was on top and the cold below they did not mix. Hot water as well as hot air rises.

Lots of time spent practising tipping the jar over with a card on. Once she had mastered this she carried out the experiments herself.

This afternoon was spent mainly in the garden. We replanted some runner beans and tried our best to get our ELC bubble machine to work. We finally gave in with the bubble machine and used bent pipe cleaners instead. Sometimes the old methods are the best - or at least the most reliable!

After that it was juice all round. Pineapple, aloe vera and strawberry. Delicious.


Bridget said...

Looks fun, more an experiment for outdoors methinks! Drink looks yummy! We have a smoothie maker, but mine aren't very adventurous

CJ said...

I love experiments, and I love seeing other peoples phots of experiments.
Yours is really good showing the two jars with the hot and cold water.

On my list to do now :-)

CJ x

Claire said...

I found this experiment from a link on your resources site CJ. I had to change it a bit in parts as I couldn't get it to work as the website suggested - but the basic idea was from one of your links. Keep up the good work with amassing the home ed resources :-)