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
2Absolute 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!
3Lord 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.
4Lord 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.
5Kelvin 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
6Charles’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.
7Straight Line Equation y = mx + by and x are variablesy = temperaturex = volumem and b are constantsm = slope of the lineb = y intercept
8Straight 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.
9Straight 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
10Charles’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
11Linear 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.
12Linear 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.
13TI-83 Linear Regression Clear Previous Data: Stat Up arrow to L1 Clear EnterMove cursor arrow to L2
14TI-83 Linear Regression Enter x values: < Enter all x values in L1 Enter after each value
15TI-83 Linear Regression Enter y values: > Enter all y values in L2 Enter after each value
16TI-83 Linear RegressionFind slope (b), Intercept (a), and correlation coefficient (r):StatMove cursor to calc82nd1,2
17Linear 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.
18Linear RegressionIs the slope positive or negative for determining absolute zero?