Nov. 12-16

This week, I learned about heat and energy and temperature.

In the past, I used to confuse the three and said that they were the same thing. However, I learned that heat is the transferring of energy, whereas, the energy itself is just energy.

I also learned about how two substances of different affect the overall temperature and the amount of heat when they are separately put into two containers of the same liquid at the same temperature.

For example, the temperature of the 200 mL of water is 5ºC, and the two substances are each put into separate containers of water at the same temperature individually. The two substances are 40 mL of water at 50ºC and 80 mL of water at 25ºC. Using my prior knowledge on the direct relationship between temperature and energy, I noted that the 80 mL had less particle motion while the 40 mL had greater particle motion since its temperature was higher.

However, I wasn't so sure if having greater particle motion in a substance that was twice as hot and had twice the volume would increase the temperature of the 5ºC water.

Problem to solve in this experiment: How would both of the
containers of water (A and B) at different temperatures affect
the temperature of the other container of water (C)?

Yet, I hypothesized that the 40 mL of water at 50ºC would increase the water temperature more because I figured that temperature, not the volume, would play as a factor in increasing the temperature.

So, in a class experiment, my group and I poured the 80 mL of 25ºC water into the 5ºC water. The temperature increased to 7ºC. Then, we got rid of the water to measure the temperature of the water correctly, since we were measuring the change in temperature after adding the 40 mL of 50ºC water to the 5ºC water. The temperature increased to 9ªC.

Therefore, I hypothesized correctly that the 40 mL water would cause greater temperature change in the 200 mL water.

But, why did the water at 50ºC have a greater change in temperature than the water at 25ºC?

Well, let's consider that the 80 mL water had more water particles than the 40 mL, and the 40 mL water had greater temperature. The question is which one has the greatest amount of energy? Without a doubt, the 80 mL had the greater quantity of energy since the volume was greater, so there are more particles than in the 40 mL as well.

Data from Wednesday's experiment shows the water
from 0-200 seconds as more heat was added to the water.

But, why is it that the 40 mL caused the 5ºC water to have greater temperature change than the 80 mL? This is so because the temperature had a greater degree of energy to make particle motion greater, in contrast to the 80 mL, which had a lesser temperature, thereby a lesser degree of particle motion. So, if it were put into the 5ºC water, then the 80 mL water would give more energy input into the water than the 40 mL water.

The 40 mL, though, had greater degree of hotness than the 80 mL since the temperature was greater.

However, the greater quantity of heat was in the 80 mL since there were more particles and more energy, since the volume is greater.

Therefore, the degree of hotness (temperature) depends on the speed of the particles, NOT the number of particles. The 80 ml water lacked in speed, but had greater mass. so mass and speed determined its greater energy input. At first, my head was swirling around this concept, but this helped to sum up the difference between temperature and energy. The degree of hotness=temperature. The quantity of hotness=energy.

I further understood how energy functioned as I understood more about what it was. There are three principles about energy:

1. Energy is  a substance-like quantity that can be stored in a physical system.
2. Energy can be “transferred” from one system to another and so cause changes in the system.



Shows the concept that temperatures remain the same
even though energy is being transferred to another
system.

3. Energy still remains the same after being transferred.

But, energy is not substantial. You can’t touch it or measure its mass on a balance. However, it can be transferred as well as stored. The third point is important because in middle school, I thought of energy transformations as something changing into something else rather than it being lost or gain in a system. To clarify this, I considered the information metaphor in class: Is music still the same even if it were on a CD-ROM or on an mp3 player? Yes, it is. Therefore, even if energy moved in different ways, energy still remains the same. It doesn't change. So, when energy from the 40 mL of water was added into the 200 mL of water, its overall energy still remained the same. It was just added into the 200 mL, but it didn't quadruple like bacteria or break down like food during digestion. Thus, the quantity of energy can be changed, but the degree energy cannot be changed.