118 terms

Science 8 Final Exam Quizlet (2017-2018)

MATTER is...
Anything with MASS and VOLUME. (and made of atoms.)
Mass is...
how much STUFF (matter) is in an object.
Volume is...
how much SPACE an object takes up.
Tool/unit for mass
electronic balance/gram
Thermal energy
The amount of movement of the particles that make up a substance. Also called "heat"
"cold energy"
Not really a thing. Just a way of saying less thermal/heat energy
Is heat matter?
No, it does not have atoms, mass, or volume
Hotter matter to colder matter
The direction or way that thermal energy/heat moves
When thermal energy/heat STOPS moving, when the substances are the SAME temperature
Definition of conduction
Transfer of thermal energy due to direct contact. The thermal energy is PASSED directly from molecule to molecule. No matter moves its position.
Definition of convection
Transfer of thermal energy through currents in a fluid. The thermal energy is CARRIED by moving molecules of liquid or gas. Matter moves.
Definition of radiation
Thermal energy transfer via electromagnetic waves, the thermal energy "JUMPS" from one substance to another without the need for matter.
CLASSIFY: Shirt being pressed by a hot iron
Conduction because the shirt and the iron are in direct contact. The thermal energy is passed from the molecules of the iron to the molecules of the shirt.
CLASSIFY: Feeling the heat of a campfire while sitting far away from it
RADIATION because the thermal energy "jumps" from the fire to you via EM waves without the need for matter.
CLASSIFY: Heated goo (liquid) in a lava lamps rises while the cooler goo (liquid) sinks in a cool swirly pattern
CONVECTION because the thermal energy is carried by the moving goo (liquid) molecules.
CLASSIFY: A cat sits on a shelf above the stove to stay warm.
CONVECTION because the air molecules are warmed by the stove, rise to where the cat is sitting and then sink back down as they cool.
CLASSIFY: On a hot, sunny August day, your Dad gets a sunburn out by the pool
RADIATION because the thermal energy "jumps" from the Sun to your Dad via EM waves, without the need for matter.
CLASSIFY: Using pot holders to pull a pan out of the hot oven
CONDUCTION because the pot holders slow/prevent the thermal energy transfer due to direct contact of your hand to the pan, thermal energy is passed more slowly from the molecules of the pan to the pot holder to your hand.
CLASSIFY: A pool heater causes the water near the surface of the pool to be warmer on a cloudy day
CONVECTION because the thermal energy is carried by the water molecules that rise toward the surface of the pool as they are heated and sink back to the bottom of the pool as they cool.
CLASSIFY: A huge rock is warmed by the Sun
RADIATION because the thermal energy "jumps" from the Sun to the rock via EM waves without the need for matter.
CLASSIFY: A piece of hair is curled by a hot curling iron
CONDUCTION because there is thermal energy transfer due to direct contact from the curling iron to the hair. The thermal energy is passed from the molecules of the curling iron to the molecules of the hair.
CLASSIFY: The vinyl siding on a house is melted/warped by a house fire across the street
RADIATION because the thermal energy "jumps" from the one house to the other via EM waves without the need for matter.
Definition of an insulator
Type of matter that blocks or reduces the flow of heat, electricity, or sound.
Definition of conductor
Type of matter that allows heat, sound or electricity to pass through it easily.
Copper, iron
These are specific kinds of conductors because they allow heat to pass through easily.
Why metal objects feel "cold" to us when we touch them with our hand
The thermal energy is transferred from our hand (the hotter matter) to the metal object (colder matter) easily since the metal is a conductor.
When thermal energy increases the molecules in a substance will...
The speed of the atoms/molecules of a substances increases.
When water vapor condenses into liquid water, then freezes into solid ice, how will the molecules change?
Particles go from zooming freely to closer together and sliding past to tightly packed and vibrating against each other.
Relationship (link) between thermal energy and temperature
As thermal energy increases, the molecules/atoms move more quickly, and the temperature of an object increases.
What ALL waves carry!
Example of Sound waves being reflected
Your teacher's voice hits the classroom wall and bounces (echos) back
Example of Light waves being reflected
White light hits a mirror and bounces back
Example of Water waves being reflected
Energy moving through a lake hits the side of a boat and bounces off
Example of Sound waves being absorbed
During a concert, the band's music is taken into the curtains surrounding the stage and does not escape
Example of Light waves being absorbed
A black t-shirt takes in all the colors of light and does not let any escape
Example of Water waves being absorbed
Under water, energy is taken in by seaweed and does not escape
Example of Sound waves being transmitted
In the hallway, you can hear a classmate's laugh pass through the closed classroom door
Example of Light waves being transmitted
Sunlight is able to stream/pass through a transparent window
Example of Water waves being transmitted
Energy is passed through a large tsunami wave
Source of wave energy
The place/action where the energy (sound, light, etc.) BEGINS
Receptor/destination of energy
The end point of the energy (sound, light, etc.), where it is "sensed"
The matter/material that the wave energy travels through
The height from a wave's resting point (middle) to the top (a crest) or the bottom (a trough)
Relationship between amplitude and energy
More energy = higher amplitude; less energy = lower amplitude
Loudness of a sound
When amplitude of a sound wave is increased
Visible light
The part of the part of the electromagnetic spectrum that human eyes can detect
Less than 1%
How much of the visible light spectrum that humans can sense
Moving matter/ vibrations
How sound is produced
Direction waves travel from a source
Outward in all directions
Vibrations of molecules (often air)
How sound energy is passed from source to destination
a rate that measures the distance an object travels in a certain amount of time
law of conservation of energy
energy cannot be created or destroyed, only transferred from one form/object to another
kinetic energy
energy of moving objects
potential energy
stored energy of object due to their POSITION
the rate at which an object moves in a certain direction (speed AND direction)
frame of reference
motion is relative; it is always described in relation to a reference point
a push or pull that can change an object's motion
unit to measure force; one of these units is equal to the force that would move a 1 kg mass one meter per second every second
a change to an object's speed (faster or slower) or direction over time
units used to represent acceleration; read as "meters per second squared"
net force
the overall or total force on an object
balanced force
when the net force is zero and there is no change in an object's motion
unbalanced force
causes an object to have a change in its motion ("leftover" force that "wins")
a force that opposes the motion of any objects that touch
air resistance (fluid friction)
the opposing force that results from the contact between air and objects moving through it
matter's resistance to a change in motion
d = rt
formula used to find rate of a moving object (speed)
(rise/run) OR (change in y/change in x)
formula to calculate slope of a line
rate of change of a line; steepness of a line
the TOTAL distance a trip takes in the TOTAL time it takes to complete the trip (including stops/breaks)
as mass increases, KE increases; as mass decreases, KE decreases
relationship between mass and KE
as velocity increases, KE increases; as velocity decreases, KE decreases
relationship between velocity and kinetic energy
gravitational potential energy
stored energy due to a position off of the Earth's surface (height)
as mass increases, PE increases; as mass decreases, PE increases
relationship between mass and potential energy
Sir Isaac Newton
scientist who studied forces and motion and came up with 3 laws of motion
N (capitalized)
abbreviation for the unit newton (used for forces)
spring scale
tool used to measure force
Newton's 1st law of motion/Law of Inertia
an object at rest stays at rest and an object in motion stays in motion unless acted on by an unbalanced force
Newton's 2nd law of motion/F=ma
the greater the mass of an object, the more force is required to move the object; the more force applied to the object, the more quickly it will change its motion
F = ma
formula to show relationship between force, mass and acceleration (Newton's 2nd Law)
Newton's 3rd law of motion (Force Pairs)
for every action there is an equal and opposite reaction
Energy in a collision
moving energy can be passed on to another object, but is never destroyed; KE is transferred
an attractive force between two masses
two variables that affect strength of gravity
mass of the objects
distance between the objects
the remains or traces of an ancient living thing preserved in rock
tectonic plates
one of the large, rigid pieces of rock that make up Earth's crust
continental drift
the gradual movement of the continents across the Earth's surface through geological time
the outermost rocky layer of Earth; rests on top of the mantle
the innermost layer of Earth
the layer inside Earth between the crust and the core
convection current
the up or down movement in a liquid or gas that is caused by differences in temperature
sea-floor spreading
the process by which magma creates new ocean crust at the mid-ocean ridges, expanding the sea bottom
mid-ocean ridge
an underwater mountain chain the circles the Earth, extending through the middle of most oceans
law of superposition
the idea that in layers of the rock, the top layer is youngest and bottom layer is oldest
plate tectonics
explains the formation and movement of Earth's plates
a mountain that forms when magma reaches the surface
super-continent proposed by Wegener when continents were all joined together as one
how new crust is created
sea-floor spreading at a mid-ocean ridge; the rocks closest to the ridge are the youngest
when old ocean plates sink into the mantle; this "recycles" or destroys old crust
divergent plate boundary
when two plates move away from each other; new crust can be formed here
convergent plate boundary
when two plates move towards each other; mountains can be formed here; old crust can be recycled here
transform plate boundary
when two plates slide past each other in opposite directions; earthquakes can often form here
edges of plate boundaries/fault lines
where earthquakes are most common to occur on Earth
sudden slip of the plates and the accompanying ground shaking
examples of slow changes on Earth
glaciers; plate tectonics; weathering/erosion; river creating a canyon
examples of fast changes on Earth
landslides; earthquakes; volcanoes; crazy weather
age of the Earth
around 4.5 - 4.6 billion years old
when humans appear on Earth
very near to the present; only about 200,000 years ago
Essential parts of a line graph
title, x- and y-axis labels, key, data points
I broke something in the science lab by accident.
Tell your teacher so you can fix it or dispose of it properly.
I forgot what to do next in a lab procedure.
1. Re-read the directions. 2. Ask a group member or another group. 3. Ask your teacher.
My shirt is on fire.
Stop, drop and roll. (and hope a classmate goes for the fire blanket!)
My partner's shirt is on fire.
Go get the fire blanket!
We will be working with dangerous chemicals in a lab (or breakable glassware, or flying objects.)
Analog wave looks like:
Digital wave looks like:
Digital signals are made by:
Storing the information in a wave as 1s and 0s (on and off)
DIGITAL is better than ANALOG because:
digital signals are EASIER to STORE, take up less SPACE, and will not break down over TIME