Presentation on theme: "-273.15 0C, 0 Kelvin Charles’s Law Absolute Zero -273.15 0C, 0 Kelvin Charles’s Law."— Presentation transcript:
1 -273.15 0C, 0 Kelvin Charles’s Law Absolute ZeroC, 0 KelvinCharles’s Law
2 Absolute ZeroTheoretically, absolute zero is the lowest temperature that can be reached.Absolute zero has never been reached.Temperatures within a millionth of a degree above C have been achieved!
3 Lord KelvinThe Kelvin scale is named after Lord Kelvin and his scale starts at 0 degrees Kelvin, which is called absolute zero.The Kelvin Scale measures the coldest temperature there can be.
4 Lord KelvinLord Kelvin said there was no upper limit of how hot things can get, but there was a limit as to how cold things can get.Kelvin developed the idea of Absolute Zero: degrees Celsius!At this temperature, no heat energy remains in a substance, the average kinetic energy is zero and all molecular motion ceases.
5 Kelvin Scale - 273.15 0C is usually rounded to - 273.15 0C The zero point on the Kelvin Scale is absolute zeroK = CKelvin is the SI unit of temperature
6 Charles’s LawV1/T1 = V2/T2By measuring and graphing the volume and temperature of a gas and extrapolating to 0 volume, absolute zero can be determined.
7 Straight Line Equation y = mx + by and x are variablesy = temperaturex = volumem and b are constantsm = slope of the lineb = y intercept
8 Straight Line Equation y = mx + bWhen b = 0, the line equation is:This is a direct proportion -- the special case of a straight line having a y-intercept = to zero.
9 Straight Line Equation y = mx + bWhen b = 0, the line equation is:In Charles Law:y = Volumex = Kelvin Temperaturem = k2 proportionality constant for a particular pressure
10 Charles’s Law Charles’s Law states: At constant pressure, the volume of a fixed amount of gas is directly proportional to its absolute temperature.K2 = V/TV1/T1 = K2 = V2/T2V1/T1 = V2/T2
11 Linear RegressionLinear regression analyzes the relationship between two variables, X and Y.For each subject (or experimental unit), you know both X and Y and you want to find the best straight line through the data.In some situations (like finding absolute zero), the slope and/or intercept have a scientific meaning.
12 Linear RegressionThe goal of linear regression is to adjust the values of slope and intercept to find the line that best predicts Y from X.The slope quantifies the steepness of the line. It equals the change in Y for each unit change in X. It is expressed in the units of the Y-axis divided by the units of the X-axis.The Y intercept is the Y value of the line when X equals zero. It defines the elevation of the line.
13 TI-83 Linear Regression Clear Previous Data: Stat Up arrow to L1 Clear EnterMove cursor arrow to L2
14 TI-83 Linear Regression Enter x values: < Enter all x values in L1 Enter after each value
15 TI-83 Linear Regression Enter y values: > Enter all y values in L2 Enter after each value
16 TI-83 Linear RegressionFind slope (b), Intercept (a), and correlation coefficient (r):StatMove cursor to calc82nd1,2
17 Linear RegressionIf the slope is positive, Y increases as X increases.If the slope is negative, Y decreases as X increases.The Y intercept is the Y value of the line when X equals zero. It defines the elevation of the line.
18 Linear RegressionIs the slope positive or negative for determining absolute zero?