Chapter 15 Physics
specific heat capacity high low
low heat capacity= quicker heating and cooling high heat capacity= slower heating and cooling
microscopic slush in ice water tends to make water density
lower
matter contains
mater contains molecular kinetic energy and possibly potential energy, not heat, heat energy flows from high to low
specific heat capacity of water effects islands and peninsulas
moderate climate because they are surrounded by water- high specific heat
matter expands when heated
molecules move faster and move apart- more energy
bimetallic strips
two pieces of sliver and bronze put together, expand at different rates, one has high specific heat other has low, used in ovens, toasters, thermometers
why does water expand when it freezes
water freezes, ice crystals, molecules expand, volume at its highest, structure of ice crystals are breaking down
specific heat capacity of water
water has higher specific heat capacity than most common materials- 4.18 specific heat- heats and cools slowly
water most dense at what temperature
water most dens eat 4 C volume at its lowest
cut small metal ring
when an iron ring is heated, the holes becomes large expanding, higher heat causes the material to expand, more narrow as it expands it close the gap
all water in lake must beat 4 C
when water is cooled to 4 C, it sinks and deeper, warmer water rises to the surface then goes to 3 C won't sink anymore
absolute zero
zero is the lowest possible temperature in which substances no kinetic energy
pour a liter of water at 40 C into a liter of water at 20 C and the final temperature of the two becomes
30 C
at what temperature do the combined effects of contraction and expansion produce the smallest volume of water
4 C
4 C
If you apply same flame to 1/2 L of water for same amount of time by how much would temperature change
specific heat of water effects North America
In summer, water temperature is cooler, in winter the water temperatures are warmer because of waters high specific heat
flame added to 2L of water
doubling molecules, doubling heat. 2L of water will rise 1 C
heat
energy transferred from one object to another because of a temperature difference
when most substances are heated, molecules inside most faster and take up more space resulting in thermal
expansion
energy ratings of food determined
food burned and energy released is measured
when you touch a potato with your finger, energy flows
from your finger to the potato
thermal expansion
get more energy, molecules move faster and move apart causing expansion, more expansion in liquids than in solids
thermal expansion in construction
golden gate bridge expand/contract 1 meter use spacers to allow movement railroads use buckles powerlines contract/expand easily
internal energy
grand total of all energies inside a substance
a substance that heats up relatively slowly has a
high specific heat capacity
water warms from 0 C to 4 C
higher temperature contract, while lower temperatures expand, so water constants at 4 C and expands at 0 C
Thermal Meter
Galileo first invented this for measuring temperature
Celsius's
Anders Celsius (1701-1744) water freezes 0 C and boils 100 C
Kelvin
Baron Kelvin (1824-1907) absolute zero, absense of all energy and 0 on this scale. boils at 373 K
Fahrenheit
Daniel Gabriel Fahrenheit (1686-1736) water freezes 32 F and boils 212 F
rotate energy temperature
particles in matter move in different ways. They move from one place to another, they rotate and they vibrate to and fro. All these types of motion, plus potential energy contribute to the overall energy of a substance. Temperature, however is defined by translational motion.
specific heat capacity
quantity of heat required to change temperature of a unit of mass of substance by 1 degree
temperature
quantity that indicates warmth with respect to some standard
thermal inertia
resistant to change in temperature
the fact that a thermometer "takes its own temperature" illustrates
thermal equilibrium