the experiment - the results

Purpose
We wanted to do an experiment to see how the sun heats different coloured things up differently.

Hyphothesis
We expected the black jar to be the warmest.

Materials.
We had three clear glass jars. A sheet of black card, and a sheet of foil.

experiment materials

Method.
We put 1 pint of water in each jar. We measured the temperature of the water in each jar and recorded it. We covered one jar with silver foil and another one with black card. We left the last one how it was. We put them out in the sun on the back door step. We measured the temperature 3 more times.

wrapped jars

Results.

black jar foil jar clear jar
2.45 (start) 17 deg C 17 deg C 17 deg C
3.40 27 deg C 22 deg C 29 deg C
4.35 35 deg C 26 deg C 35 deg C
6.55 37.5 deg C 28 deg C 33.5 deg C

Conclusions.
The foil jar stayed coolest. Foil is good at keeping heat out.
The clear jar warmed up fastest, but then started to cool down again.
The black jar kept getting warmer very slowly even when the clear jar was cooling down. The black jar was keeping its heat.

Mummy and Daddy thought that part of the reason we didn’t get the result we expected was because there was a gap between the black wrapping and the jar. If we were going to do the experiment again, we would try it painting the jar black, or using tin cans and painting one of them black.

This entry was written by Jax, posted on Sun Jun 4 2006 at 14:48, filed under Big, things that go bang. Bookmark the permalink. Follow any comments here with the RSS feed for this post. Both comments and trackbacks are currently closed.

6 Comments

  1. Sarah
    Posted Sun Jun 4 2006 at 15:21 | Permalink

    Great experiment - did Big enjoy the process? :)

  2. Jax
    Posted Sun Jun 4 2006 at 16:49 | Permalink

    She says yes. :grin:

  3. HelenHaricot
    Posted Sun Jun 4 2006 at 18:14 | Permalink

    good writing up.

  4. Jax
    Posted Sun Jun 4 2006 at 18:40 | Permalink

    We think it could be time for a blog of her own ;)

  5. Libertus
    Posted Tue Jun 6 2006 at 9:43 | Permalink

    That’s an excellent experiment because Big has another hypothesis to test as a result. The insulating material is certainly relevant but is the air-space between the insulation and the jar relevant?

    Have you shown Big how a thermos flask is constructed?

  6. Tim
    Posted Tue Jun 6 2006 at 18:38 | Permalink

    Interesting point about Thermoseseses (Thermi?).