6: Temperature Flashcards
Kinetic Energy (J)
1) Define
2) Formula
3) 1 J =
4) What happens if temp increases
1) Energy which a body possesses by virtue of being in motion
2) KE = 1/2 mv2
3) 1 Joule = 1 kg m2 s-2
4) The particles move around faster thus exerting higher pressure
Define Heat
The Cumulative Total Kinetic Energy of all molecules in a substance
Define Temperature
Proportional to the Average Kinetic Energy of all the molecules in a substance
(scalar quantity - magnitude, no direction)
1) What happens when we go up within the atmosphere?
In the thermosphere:
2) Temperature
3) Heat
The density of air changes
(number of molecules decrease with substantially height)
2) High energy molecules (due to magnetic field) = high Average Kinetic Energy
3) Low number of molecules = Total Cumulative Kinetic Energy is low
Define Specific Heat Capacity of a a substance
The amount of heat required to raise the temperature of 1 kg of a substance by 1 degree
Specific Heat Capacity of
1) Water
2) Land
3) Which heats up/cools down quicker due to this
1) 4190 J kg-1 Degree Centigrade
2) <1000 J kg-1 Degree Centigrade
3) Land
Water (Initial state, 10* C) 1 kg of water 1) 11 *C 2) 12 *C 2 kg of water 3) 11 *C 4) 10.5 *C
1) 4190 J energy
2) 8380 J energy
3) 8380 J energy
4) 4190 J energy
Given a constant heat source
1) Mass
2) Specific Heat Capacity
1) The greater the mass (which energy s distributed), the lower the temperature change
2) The higher the specific heat capacity of the object, the lower the temperature change
Temperature Calculation Find density where: Pressure is 1013 hPa, Universal gas constant is 287.05 J kg-1 K-1, & Temperature is 30 *C
p = P/RT = 1013 x 100 (convert to Pa) ----------------------- 287.05 x (30 + 273.15) (convert to K) = 1.16 kg m-3
check units
p = kg (mass) m-1 s-2 (acceleration)
—————————————————-
(kg m2 s-2 (Joule) kg-1 K-1 (R is J kg-1 K-1) x K
= kg m-3
Conduction 1) Define Give a: 2) Very good conductor 3) Poor conductor 4) Good insulator
1) Energy transferred by contact between molecules
2) Metals
3) Air
4) Air
If the initial state = 10 *C
What would be the final state, if 4190 J energy were added to:
1) 1 kg Water
2) 1 kg Sand
1) 11 *C
2) 15.24 *C
Convection
1) Define
2) Where does it occur
1) Transfer of heat by the movement of a fluid (liquid or gas) between areas of different temperature
2) Troposphere, especially in tropics
Advection 1) Define Horizontal advection 2) Warm air come from 3) Cool air come from
1) The transport of a substance or quantity by bulk motion of a fluid. The properties of that substance are carried with it
2) Nullarbor
3) Fremantle doctor (sea breeze)
Solar Radiation
1) Define
Radiation is energy travelling as waves or particles (electromagnetic radiation through space)
Diurnal Cycle
A diurnal cycle is any pattern that recurs every 24 hours as a result of one full rotation of the planet Earth around its axis
Diurnal cycle
When does maximum temperature occur on Earth
3 pm, lag as it takes time for earth to start emitting radiation back
Diurnal cycle
When does minimum temperature occur on Earth
6 am, once the sun has set, the earth is emitting more radiation than it is coming in which keeps happening throughout the night until just before sunrise
Hottest month
Even though summer solstice is 22nd Dec, it is February or even early March, lag between maximum incoming radiation and maximum temperature
Temperature Inversion (Night)
when we have clear cloudless NIGHT with low wind, earth surface gets so cool, that the air on top of the earths surface gets very cold, the air further aloft is warmer
so we have temp increasing with height - radiative inversion.
Temperature Inversion (Day)
As land surface warms up, it warms the air above it so the air on top is cooler, during the day it is generally typical to find temperature decreasing with height
Control of temperature in troposphere
Altitude
Temperature decreases with higher altitude
Control of temperature in troposphere
Clouds
1) Day
2) Night
1) Temperature decreases with higher cloud clover
2) Temperature increases with high cloud cover
(no radiation from sun but from surface)
Control of temperature in troposphere
Winds
1) Day
2) Night
1) Temperature decreases with high winds
(if from cool region)
2) Temperature increases with high winds
(higher kinetic energy)
Thermometry
Basic Principle 1
Materials expand as temperature increases
Thermometry
Basic Principle 2
Resistance to current flow increases as temperature increases
Heat transfer occurs…
from hot to cold regions
