a) Read and translate the text before watching the video.
Here's a bucket of hot water at 50ºC.
And here's a cup of freshly boiled water at 100ºC. In which of these two containers are the water molecules moving faster?
a) The bucket.
b) The cup.
The cup, because the degree of hotness in the cup is higher, so its molecules move faster.
Do you think that you have more hotness in the cup than in the bucket?
In that case, if the water in the swimming-pool is a bit cold for you, do you prefer to add the water in the cup or the bucket?
Let's do an experiment to find out:
- Suppose you have two swimming-pools: one yellow and one blue, with cold water.
- Pour the cup of boiling water into the yellow one . Is the water hotter? Any difference?
- Pour the bucket into the blue one. What's the water like now?
Even though the water in the cup was considerably hotter than in the other container, it is better to add the water in the bucket into the swimming-pool to get it warm. Why is this?
Look at this:
The bucket contains many more water molecules moving than the cup.
The temperature of each molecule in the bucket is 50ºC, and the temperature of each molecule in the cup is 100ºC.
If I put 100 dollar bills in the cup and 50 dollar bills in the bucket, which one do you prefer?
There is more money in the bucket.
With temperature it is the same, the degree of hotness is higher in the cup, the quantity of hotness is greater in the bucket.
We know that the speed of the molecules determines the degree of hotness or temperature (the number of molecules is not important).
The quantity of molecules is more in the bucket, so the quantity of hotness is more, too.
The quantity of hotness or heat depends on the speed and quantity of molecules.
The degree ot hotness or temperature just depends on the speed of molecules.
b) Answer the following questions:
- In which of these two containers are the water molecules moving faster?
- Why doesn’t the water in the swimming pool get hot when the boy pours the cup into it?
- Where is there more quantity of hotness, in the cup or in the bucket? Why?
- Where is there more degree of hotness, in the cup or in the bucket?
- The quantity of hotness or ……….. depends on ………………………………………
- The degree of hotness or ……………… depends on ……………………………………