Heat and Temperature

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• Heat and Temperature
• Accuracy
• and
• Precision

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Heat Temperature
HEAT TEMPERATURE
Definition
Measuring Device
Units
3
Heat Temperature
HEAT TEMPERATURE
Definition Flow of thermal energy Average kinetic energy
Measuring Device
Units
4
Heat Temperature
HEAT TEMPERATURE
Definition Flow of thermal energy Average kinetic energy
Measuring Device Calorimeter Thermometer
Units
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Heat Temperature
HEAT TEMPERATURE
Definition Flow of thermal energy Average kinetic energy
Measuring Device Calorimeter Thermometer
Units Joules, calories C, F, K
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Heat Temperature
HEAT TEMPERATURE
Definition Flow of thermal energy Average kinetic energy
Measuring Device Calorimeter Thermometer
Units Joules, calories C, F, K

• The omission of "degree" symbol for the Kelvin
  scale indicates
• that it is not relative to an arbitrary reference
  point such as the
• Celsius and Fahrenheit scales.

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Measuring Devices
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(No Transcript)
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Does your desk top or the desk leg feel Cooler?
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You are experiencing Heat?
C
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Explanation

• Heat flows from you to the desk because the desk
  is cooler than you.
• The top of the desk is an insulator.
• The metal leg is a conductor.
• The metal conducts heat away from your skin. And
  the sensation of losing heat makes you feel cold.
  Since heat leaves your hand touching the metal
  at a faster rate it feels colder.

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Is the shooter accurate/precise?
a
a
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Accuracy refers to how close a measurement is
to the true or correct value for a quantity.
Precision refers to how close a set of
measurements for a quantity are to one another,
regardless of whether or not the measurements are
correct.
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Accuracy vs Precision
a
a
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See Notebook For this example
Larry, Curly and Moe are each given the same type
of metal and are asked to measure its density.
The actual density of the metal is 3.0 g/ml
however they are not told this. They take four
sets of measurements and use these to calculate
the density of the metal for each set of
measurements. Their results are given below.
Larry Curly Moe
2.5 g/ml 4.0 g/ml 4.0 g/ml
2.7 g/ml 2.0 g/ml 4.1 g/ml
3.1 g/ml 1.0 g/ml 4.1 g/ml
3.3 g/ml 5.0 g/ml 4.2 g/ml

• Who is the most precise?
• Who is the most accurate?
• What is the percentage error (experimental error)
  of Larrys reported density measurement?

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Larry, Curly and Moe are each given the same type
of metal and are asked to measure its density.
The actual density of the metal is 3.0 g/ml
however they are not told this. They take four
sets of measurements and use these to calculate
the density of the metal for each set of
measurements. Their results are given below.
Larry Curly Moe
2.5 g/ml 4.0 g/ml 4.0 g/ml
2.7 g/ml 2.0 g/ml 4.1 g/ml
3.1 g/ml 1.0 g/ml 4.1 g/ml
3.3 g/ml 5.0 g/ml 4.2 g/ml

• Who is the most precise?
• Moe, he has the lowest range (0.2).
• 2. Who is the most accurate?
• Curly, his average is closest to 3.0 (the
  accepted value).
• 3. What is the percentage error (experimental
  error) of Larrys reported density measurement?

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Percentage Error
Larry Curly Moe
2.5 g/ml 4.0 g/ml 4.0 g/ml
2.7 g/ml 2.0 g/ml 4.1 g/ml
3.1 g/ml 1.0 g/ml 4.1 g/ml
3.3 g/ml 5.0 g/ml 4.2 g/ml
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Percentage Error
Larry Curly Moe
2.5 g/ml 4.0 g/ml 4.0 g/ml
2.7 g/ml 2.0 g/ml 4.1 g/ml
3.1 g/ml 1.0 g/ml 4.1 g/ml
3.3 g/ml 5.0 g/ml 4.2 g/ml
 
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Homework

• Worksheet Chapter 2 - 2