thermal energy
DESCRIPTION
Thermal Energy. Thermal Energy. Matter is made of particles that are in constant random motion The faster the particles move, the warmer an object gets. Kinetic Theory. This is the basis of Kinetic Theory. Temperature. Temperature is the measure of average kinetic energy of an object - PowerPoint PPT PresentationTRANSCRIPT
Thermal Energy
Thermal Energy
Matter is made of particles that are in constant random motion
The faster the particles move, the warmer an object gets
Kinetic TheoryThis is the basis of Kinetic
Theory
Temperature
Temperature is the measure of average kinetic energy of an object
Temperature and energy are directly related
The more kinetic energy, the higher the temperature
The more potential energy, the lower the temperature
Temperature
The standard unit for temperature is Kelvins (K)We also use Celcius and
FarenheitKelvin -273 = ˚C
Why does the ice melt?
Thermal Energy
The total of the Kinetic Energy and Potential Energy of all particles in an object.
Thermal energy and temperature are directly related
Thermal energy and mass are directly related
Thermal Energy and Mass
Heat
Thermal energy that flows from something at a higher temperture to something at a lower temperature is called heat
Heat is measured in Joules (J)An example is when you get up from
a chair and it is warm to the touch. In science, ther is no cold, only
absence of heat
Specific Heat
Specific heat is the amount of heat needed to raise 1 kg of a substance 1 ˚C
It is measured in J/kg ˚C
SubstanceSpecific Heat
Capacity at 25oC in J/goC
H2 gas 14.267He gas 5.300H2O(l) 4.184
ethyl alcohol 2.460 air 1.020
magnesium 1.020 nickel 0.440 zinc 0.39
copper 0.385 brass 0.380 sand 0.290 silver 0.240
tin 0.21 lead 0.160
mercury 0.14 gold 0.129
Specific Heat
Water has a very high specific heat.
It is good as a coolant in radiators
Formula for Change in Thermal Energy
The formula for thc change in thermal energy is Q = mCΔTQ – the change in thermal energyM – mass of the objectC – specific heat of the substanceΔT – change in temperature (T
final – T initial)