Vocab
Define the term phase:
state of matter
solid- vibrates
liquid- move around eachother
gas- very fast
When energy is transferred, what does the interaction do to the two materials?
leaves one with more energy and the other with less
the total amount of energy NEVER changes
What are freezing points?
What are boiling points?
freezing point is when a liquid changes to a solid
boiling point is when a liquid changes to a gas
Finish the statement: Work can only be...
done in the OPPOSITE direction of the force
Tell us what a phase change is...
Change from one state of matter to another
What is a change from one state of matter to another?
phase change
List 5 forms of energy
light, heat, sound, nuclear, sound, solar, mechanical, chemical...
Which type of heat transfer is due to uneven heating of liquids and gases?
convection- the cycle
What is the Kinetic Theory of Matter?
All matter is made of tiny moving particles
Define the term energy...
the ability to do work
List 4 phase changes:
melting/freezing
boiling/condensing & evaporation
Describe the energy transfer when a bell rings in school
electrical, to mechanical, to sound
Which type of heat transfer is felt from a distance?
radiation
What units are work and energy measure in?
work - Joules
energy - Joules
What is the difference between potential energy and kinetic energy?
Weight is the measure of what???
Potential is stored energy -- energy of condition or position
Kinetic is energy of motion
weight is a measure of gravity's pull on an object
Which phase change(s) happen at 0oC
and 100OC?
0oC = freezing and melting
100oC = condensing & boiling
How do you know a phase change is occurring on a graph?
constant (horizontal) line
the temp is NOT increasing or decreasing
Which type of heat transfer requires direct contact?
conduction
Law of conservation states...
energy can be transformed or transferred
energy cannot be created or destroyed
Why does a pot of hot water have MORE heat energy that a cup of hot water?
Which will have a higher temperature?? THINK!
pot of hot water has more heat energy bc there are more particles
Both have same temperature
Which phase changes absorb heat?
Which phase changes release heat?
absorb melt & boil
release freeze & condense
Describe how melting, evaporation and boiling are similar.
1. all absorb heat
2. particles speed up
3. physical changes
Define: wavelength
crest
trough
compression
wavelength - distance from crest to crest
crest - top of a wave
trough - bottom of a wave
compression - squished part of a compression wave
Where in a pendulum's swing does the kinetic energy decrease and the potential increase?
at the bottom the kinetic is greatest so on the way up it is losing kinetic and gaining potential