Curving of Grades

1
Curving of Grades

• Grades are curved with the following formula
• curved grade (78/exam average)exam grade
• Suppose the exam average is 60
• The average score is a 78 C
• curved grade (78/60) exam grade
• Note 78 will change if exam average gt 78

2
Basic Ideas of Thermodynamics

• Molecules are in motion and contain KE
• Temperature is a Measure of the
• Kinetic Energy
• Temperature Scales
• Relative Absolute
• Calibration Celsius Fahrenheit Kelvin
• Freezing 0 oC 32 oF 273 K
  
• Boiling 100 oC 212 oF 373 K

3
Kelvin Scale

• The average KE is proportional to the Kelvin
  temperature (absolute Scale.)
• Room temperature (20oC) is 293 K
• Kelvin scale implies that at 0 K there is no
  thermal motion.

4
Heat

• Heat is the rate of transfer of Thermal Energy
• The first two involves a molecular transfer
• Conduction -- hot source touches the object
• Convection -- use of a fluid to transfer energy
• to the object.
• Radiation -- electromagnetic waves transfer
  energy by being absorbed by the object.

5
Storage/Release of Thermal Energy (Potential
Energy)

• Heat Capacity -- stores by virtue of the
  molecules Kinetic Energy
• Phase Transitions energy is /absorbed or
  released because of changes in the
  molecular state.
• Absorbing - melting, evaporating, sublimating
• Releasing - freezing, condensing, deposition