Thermodynamics is a branch of physics that is concerned with heat energy and temperature and their interaction with matter.
More correctly, thermodynamics involves examining the principles behind the movement of heat.
Some concepts may already be known to you such as the idea of heat transfer via conduction convection and radiation. You may already know about the changes of state, and that certain substances will melt or boil a different temperatures. But what are the physics principles as to why changes of state occurs?
In these series of lessons, will explore some Thermodynamic concepts, (though not exhaustive.)
We will start by looking at what temperature is, and then examine to important properties of materials called the specific heat capacity and latent heat.
We will also examine how heat is transferred from substance to substance via conduction convection and radiation, and look at the rate of heat transfer.
More correctly, thermodynamics involves examining the principles behind the movement of heat.
Some concepts may already be known to you such as the idea of heat transfer via conduction convection and radiation. You may already know about the changes of state, and that certain substances will melt or boil a different temperatures. But what are the physics principles as to why changes of state occurs?
In these series of lessons, will explore some Thermodynamic concepts, (though not exhaustive.)
We will start by looking at what temperature is, and then examine to important properties of materials called the specific heat capacity and latent heat.
We will also examine how heat is transferred from substance to substance via conduction convection and radiation, and look at the rate of heat transfer.
1. Heat vs Temperature
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Colloquially when it is a hot day we refer to the temperature. So people often equate heat with temperature. But they are not the same. When you take a pizza out of the oven, the crust does not seem to be as hot as the melted cheese on top however they are both the same temperature. This video examines the difference between temperature and heat. It also examines the zeroth law of thermodynamics and why substances feel cold. |
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2. Specific Heat Capacity Explained
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Take two beakers, one filled with oil and one filled with water. Place both on an identical heat source, for the same amount of time. You predict that they will both be raised to the same temperature, but you would be incorrect. Different substances will heat differently to other substances. This is related to a concept called specific heat capacity, the idea of how much a substance temperature might rise when a certain amount of energy is applied to it.
This video examines the physics principles, includes some everyday examples, and also provides some mathematical modelling. Also examine the worked example, and try some problems yourself |
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3. Latent Heat Explained
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Place a cup of iced water onto a heat source and you will find that the temperature remains at 0° C until the ice has completely melted. Why is this the case? This video examines the concept of latent heat: the idea of energy going into a system not causing an increase in temperature, but instead changing the state of substance. |
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4. Sea Levels rising - an application of thermal expansion
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One of the concerns related to climate change is rising sea levels. As atmospheric temperatures increase, and therefore as ocean temperatures increases, the volume increases.
Global systems are by nature very complex, but the principles of thermal expansion, is relatively straightforward to comprehend. This video discusses the fundamental physics principles as to why sea levels are contingent upon changes in the climate |
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5. Blue Ocean Event - an application of thermodynamics
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The presence of Arctic ice maintains the Arctic sea temperatures to close to 0°C. This Arctic ice is present throughout the year, from Winter to summer.
The physics principles underpinning this is latent heat. The Blue Ocean event is a case in climate science where the arctic is ice free for some period. This has ramifications to arctic sea temperatures, and therefore can have drastic affects in global temperature systems. This examines the physics behind it. (This video provides the physics behind it, there is an abridged version that cuts out some of the physics explanations |
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6. Conduction, Convection, Radiation
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There are a number of ways we can explore this concepts further.
One aspect of most high school physics course on kinematics, is that they only concern themselves with constant acceleration. In reality however, acceleration, like displacement and velocity, can chance with respect to time.
Velocity is the rate of change of displacement. Unit: m/s2
Acceleration is the rate of change of velocity.
So what is the rate of change of acceleration?
The answer to that is the jerk. So slope of the acceleration vs time graph is the jerk. Unit: m/s3
We can go further.
What is the rate of change of the jerk?
Well it's the snap. Unit: m/s4
Can we go further? Yep. The rate of change of snap is the crackle. Unit: m/s5
I think you can guess the next one.
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- pHET graphing animation - this interactive from the University of Colorado pHet team is a great way to demonstrate the relationship between motion and its graphical analysis. That why I used it in my video. At this time its Java based so will only work on PC/Mac
