Learning Objectives

• How to light a match!
• How to light a fire
• How to measure temperature in Celsius
• The Heat Equation and terms
• The concepts of Heat, Energy and Temperature.

Wednesdaywas just taking role and welcoming students to the new school year.

Thursday and Friday: To kick off our unit on Thermodynamics, we set up simple ‘furnaces’ (called Thermal Containment Systems) so that we could light Dorito’s on fire and then heat a small can of water. By measuring the amount of water in mL and recording the starting and ending temperatures, we can calculate how many joules the system captured. Along the way we learned that Graduated Cylinders are used to measure volume in mili-Liters and that water has a density of 1 gram per mL. We learned about ‘delta T’ as the change in temperature, and the value that matters in the heat equation. And for many students, we learned simply how to light a match.

Learning Objectives

• The Paleocene/Eocene Thermal Maximum: What caused it, what the impact on Earth was and why it is relevant today.
• The history and usage of the joule vs the calorie vs the KiloCalorie (known as food calories)
• Energy defined (the ability to do work)
• work defined (applying a force over a distance)
• that Heat is one form of energy and is measured (in science and engineering) in joules..
• That Temperature will increase if Heat is added and decrease if Heat is removed.

Monday-Wednesday: Clark first wrote on the white board, the heat equation and described the meaning of each of the terms. Heat (Q) is Energy measured in Joules! We then discussed how Heat is often confused with Temperature.. but the goal of this lab (the burning chips lab) is to learn to understand that by adding (heat) energy into a system, it will Change Temperature. (delta T). We then spent some time considering Earth’s changing climate including the history of the Ice Ages (we are still in them!) and how Earth’s temperature naturally ‘flips’ from warm periods to cold periods due to Volcanic Eruptions (which heat it up!) and the much longer, natural cooling cycles (Earth’s oceans pull CO2 out of the atmosphere to form Limestone). Of special interest however, is the Paleocene/Eocene Thermal Maximum, which was a catastrophic heat of the Earth 55 million years ago. This led to a mass die off of Marine life globally and forced land animals to shrink. Along the way, students had time to consider their Poster Project (the deliverable of the Burning Chips lab) after Clark passed out the descriptor. 

Thursday and Friday: We continued our discussion of global heating and discussed El Nino as an ocean dynamic that redistributes heat around the planet. We also stepped into the topic of Kinetic Energy and how we calculate it. This calculation though also required that we take a moment to discuss Velocity (distance/time) and how we can measure it directly. In this lab, since students would be throwing tennis balls into the air, we first discussed Conic Sections and considered Parabolas.. which are the natural trajectory that thrown objects follow. In our case, since the Arc-length for a parabola requires calculus, we approximated the arc-length as semi circles.. (we can then use the equation for circumference to solve for the semi-circle.  

Learning Objectives: 

Continuing to refine our understanding of: 

• Velocity = distance/time (m/sec)
• Kinetic Energy = 1/2 mV^2
• Work = Force x distance.
• Energy is conserved, but can change forms.

New Learning Objectives:

• How does the Kelvin temperature scale differ from Celsius and Fahrenheit?
• What is the Boltzmann Energy Distribution graph an illustration of?
• How did Newton, Leibniz and Emilie Du Chatelet contribute to the development of the theory of energy?

Monday: Clark first considered the different temperature scales in use today. Most people are familiar with the Fahrenheit scale and many are conscious of the Celsius scale. In science however, we frequently use the Kelvin Scale, which starts at Absolute Zero.  From Clark showed students a simulation of gasses and how they behave as they heat up. The purpose of this demonstration, is to illustrate that, for a collection of particles (in a gas, solid or plasma!) each individual particle will have its own speed and kinetic energy, but its the collection of these energies that determine the Temperature of the system. This then, leads to the Boltzmann Energy Distribution graph. 

Tuesday: Clark passed out the Report Guidelines for last Friday’s Kinetic Energy Lab ( Kinetic Energy of Tennis Balls ).. with some time to discuss. This project is a report, not a poster. Due next Tuesday! We then spent some time reflecting on the Abstract Concept of Energy itself.. it is NOT something you can hold in your hand.. it is the ‘potential’ to do some work. Interestingly, Newton was not clear on the concept, nor were many of his contemporaries. The PBS VIdeo: Einsteins Big Idea considers this moment with the sequence describing the contributions of Emilie Du Chatelet. (see assignment above). Student were to take a page of notes on this sequence.

Wed-Thursday: Nepal glacial collapse, Video: Start of Chasing Ice, up through the Ice Core Data..

Friday: What does it mean to be transparent? Review of what students have already learned about the greenhouse effect.. graphic of atmospheric transparency and ‘incoming radiation vs outgoing radiation’. Review of exponential increase of CO2 (today and in times past)… emphasizing the historic nature of this particular increase. Closeup of last 40 years of CO2 and discussion of why we have ‘seasonal’ fluctuation. Also on Friday, a deeper discussion of how to take notes including ‘catching what you can’ and annotating your own notes.

Learning Objectives: 

• The Four States of Matter
• What are ‘intermolecular forces’?
• How does increasing temperature affect an objects ability to stay solid? Liquid? Gas?
• What terms do we use to describe phase changes?
• Buoy vs Buoyancy vs Buoyant Force; what’s the difference?
• How to determine the Buoyant force on an object
• Phase Change diagrams.
• The First Law of Thermodynamics
• How to Calculate Percent Error. 

Monday: We first watched the next 20 minutes of Chasing Ice in which the increasing frequency and intensity of global, weather related disasters was described along with the data that Reinsurance companies are looking at when they consider their financial gains and losses. After wards, the students were given work time to complete their last round of labs and activities (the first thermodynamics and heat poster as well as their kinetic energy of Tennis Balls report).

Tuesday: Clark introduced the concept of States of Matter and Phase Changes. For historical interest, we also considered how the Ancient Greeks considered matter and energy. (see diagram at right). As part of this discussion, students built Candle-powered pinwheels.. (as the simplest example of a Heat Engine).. and as they ‘came to life’ we considered ‘why’ the pinwheel began to turn. This led to the topic of Bouyancy and Bouyant forces (what is a Bouy?)

Wednesday: Class began with a review of phase changes, with Clark drawing a sketch on the board showing how the temperature of an object heating from solid to plasma transitions in time. The central point is that when something is going through a phase change, energy is required, but its not changing temperature, its changing phase. From here we stepped into a simply lab in which students were given insulated containers which were then filled with a known mass of very hot water. We then added ice cubes to the hot water and after the ‘system’ reached a constant temperature, we calculated how much energy must have been consumed during the melting process. This then led to our calculation of Heat of Fusion for Water (how many joules per gram does it take to melt water). The students will do a 1-2 page write up of this experiment. Due next Tuesday. 

Thursday-Friday: Clark first introduced the Laws of Thermodynamics. (there are 4). The First Law of Thermodynamics says that for a closed system, energy can be neither created or destroyed, it can only change form. Mathematically, that results in the equation: Delta Q1 +Delta Q2 + Delta Q3 = 0. In other words, if one object loses heat (i.e. -1000 joules) and a second object Gains heat (i.e., + 1,000 joules) than the SUM of those two must add to ZERO. In our lab, we had heat doing three different things: The Hot water was cooling (losing heat), the ice was Melting (phase change!) which TAKES HEAT (gaining heat).. and the newly formed Ice Water was warming up (gaining heat). Since we can use the heat equation to determine how much heat the two masses of water used to warm and cool respectively, the only unknown is Q3, the Heat to melt the ice. Once we have this, we can simply divide that value by the mass of Ice to determine the HEAT OF FUSION (joules/gram). 

Additionally, we discussed the concept of Percent Error Calculations (how to determine how far off we were from the accepted value of 333 joules/gram). The remainder of the period was ‘project time’ which will continue into Friday. 

Learning Objectives for the week: 

• How and why to use significant figures and carry them through calculations.
• Volume of cylinder 
• Density = mass/volume
• Percent error calculations
• Buoyant forces and predicting the ‘water line’ for a floating object

Monday was Labor Day. Tuesday and Wednesday we focused on how to use Significant figures in measurement and calculations. To put this into practice, students measured the diameter and height of a candle (a decent ‘classical’ cylinder) and then using these values, calculated the volume of that candle. From here we then determined the density (of wax) of their candle and based on the ‘law of buoyant forces’ (that the Volume of water displace is dependent on the Mass of the object which is floating (or immersed). From here we predicted the ‘water line’ (often painted on the sides of ships) to predict at what height the candle would float in the water (or from the student’s perspective, how much of the candle would remain above water).

Thursday we did one last lab, Hot bolt into Cold Water.. In this lab, students began with a known sample of cold water. We then dropped a Hot piece of metal into the cup of water and based on the final temperature (of the system in Thermal equilibrium) students were able to determine the Specific Heat Capacity of the metal.

Friday is the final, End-of-Unit test and the last day for students to submit their Main Lesson Portfolio. Review guide for Thermodynamics end of Unit test

Note to Clark: next year bring in a Helium balloon and a ‘regular’ balloon filled to the same volume. Same balloon, same size, same number of particles. Introduce elements on periodic table. Weight of He vs weight of N2, O2, etc.. very different. Affects buoyancy.. How much does does the He weigh? Gram scales to weigh He up.. to way Air (compressed) down.