Two math experiments

Today grade 9s did two experiments. One looked at the cooling of hot water, and the other looked at the frequency of sound produced when we blow over the neck of a bottle compared with the depth of water in the bottle.

We measured the depth.

We blew across the mouth of the bottle to make a noise, which is not always an easy task!

We used the app “sonic tools” a free download, to measure the frequency of sound. We then decreased the amount of water in the bottle and tried again and again and again.

We made tables of values and made graphs

We are looking at trends and scales and axes, and making sure that we are communicating clearly.

For the temperature experiment we poured hot water into a mug, and took temperature readings each minute.

After 5 minutes, we made a best fit line and extrapolated to predict the temperature at 10 minutes and 15 minutes.

We made clear graphs…

And compared our real data at 15 minutes with the predicted temperature at 15 minutes. In most cases, the water had not cooled as much in reality as predicted. We realized that the data is not linear, but gently curved.