Earth Surface & Energy Force – Physics
This Physics chapter covers earth surface and energy force.
displacement
distance and direction of a body’s position
velocity
speed of an object and direction of motion (vector)
acceleration
change in speed or direction per unit time
inertia
tendency of a body to resist changes in motion
force
push or pull between bodies
balanced forces
forces on one body have equal size but opposite direction
instantaneous speed
speed at a single point in time
friction
force that opposes motion between two touching surfaces
gravity
force of attraction between any two bodies
momentum
product of mass and velocity
static friction
force keeping two unmoving objects from moving past each other
weight
the gravitational force exerted on a body
chemical potential energy
energy stored in bonds between atoms
gravitational potential energy
energy of position (height)
joule
SI unit of energy
kinetic energy
energy of motion
mechanical energy
sum of PE and KE in a system
elastic potential energy
potential energy stored in an object that stretches or compresses
heat
thermal energy that moves from hot areas to cold areas
convection
heat transfer by movement of particles in a fluid
conduction
heat transfer by touch
heat engine
device that converts heat energy to mechanical energy
temperature
average kinetic energy of particles in a material
heat mover
device that removes thermal energy from one location and transfers it to another location at a different temperature (ex. air conditioner)
Joule
the unit for work is the:
Newton
the unit for force is the:
power
the rate at which work is done ( work/ time )
machine
a device that allows you to do work in a way that is easier
mechanical advantage
the number of times a machine increases a force exerted on it ( output force/ input force )
1st class lever
What class lever is this? effort———-load
^Ex: see saw, scissors, oar
2nd class lever
What class lever is this? effort—-load——
^
Ex: bottle opener, wheelbarrow
3rd class lever
What class lever is this? load—-effort—–
e ^
Ex: rake, fishing rod, tweezers
inclined plane
a flat, sloped surface that acts as a simple machine
wedge
a device that is thick at one end and tapers to a thin edge at the other end
screw
an inclined plane wrapped around a cylinder
lever
a rigid bar that is free to pivot or rotate on a fixed point
fulcrum
the fixed point on which a lever is free to pivot or rotate
wheel and axle
a simple machine made of two cylindrical objects fastened together that rotate around a common axis
pulley
a simple machine made of a grooved wheel with a rope or cable around it
fixed pulley
the type of pulley that requires more effort than the load to lift the load from the ground, does not need to be pushed or pulled up or down
movable pulley
a type of pulley that moves with the load and allows the effort to be less than the weight of the load
compound machine
a machine that utilizes two or more simple machines
doppler effect
the change in frequenct of a wave as its source moves in relation to an observer
dry cell
an electrochemical cell in which the electrolyte is a paste
wet cell
an electrochemical cell in which the electrolyte is a liquid
potential energy
stored energy that results from the position or shape of an object
parallel circuit
an electric circuit with multiple paths
kinetic energy
energy that an object has due to its motion
temperature
speed of sound depends on the type of medium as well as its _______________.
light
which is faster, light or sound?
reflects
the color of an opaque object is the color of the light it _________.
magenta
red light + blue light =
cyan
blue light + green light =
yellow
red light + green light =
red
magenta pigment + yellow pigment =
green
yellow pigment + cyan pigment =
blue
magenta pigment + cyan pigment =
light
when the electron calls back a photon is given off, creating this:
solar energy
energy from the sun
specific heat
measure of energy needed to raise the temperature of an object (water: 4.184 J/(kg K))
radiation
transfer of energy by electromagnetic waves
thermal energy
total kinetic and potential energy of all the particles in a substance
interference
combination of two overlapping waves
refraction
the bending of a wave as it changes speed between mediums
wavelength
distance between crests on a transverse wave
medium
the matter a wave travels through
transverse wave
a wave in which matter moves at right angles to the wave direction
What are the earliest forms of life on Earth
Single Cell Organisms (bacteria) that evolved from the “Primordial Soup” in the depths of the oceans
When did the cyanobacteria form?
3.5 billion years ago
Cyanobacteria group together to form major structures called what
Stromatolites
Cyanobacteria use the sun’s energy to do what
Photosynthesize (make there own food)
evolution
The gradual change of characteristics within a population, producing a change in species over time
natural selection
process that drives evolution by charles darwin who wrote the origin of species
Modern synthesis
concept that evolution was a process of gradual adaptive change in traits among populations
Gene pool
the entire collection of genes within a given population
mutation
a change of the DNA sequence of a gene
genetic drift
recognized to influence the evolution of new traits. a small change in frequency of particular genes simply due to chance influence.
gene migration
the introduction of new genes from the immigrant results in a change of the gene pool
Hardy-Weinber Law of Equilibrium
study of genetics shows that in a situation where random mating is ocurring within a population: formula is p2+2pq+q2=1
When was our sun formed
4.6 billion years ago
Where did the dust and rock come from that formed our Earth
Formation of the sun
How old is our Earth
4.5 billion years old
There was air on Earth at its beginning
False
What elements/compounds were present on Earth at this time
Iron, nickel, and carbon
What was Earth like at its birth
It was a hot ball of magma on the surface and had an iron and nickel core in the center
What planet collided with Earth
Thea
Both planets turned into
Magma (rocks)
How was the moon formed
From left over debris from the Earth’s collision with Thea
How close was the Earth was the Moon when it was formed? How far is it from Earth today?
It was very close and has moved farther away
At this point how long does a day on the Earth last
6 hours
How did water end up on Earth
In crystals that were in meteors from space
At this point in time the Earth has cooled down enough to allow what to form on its surface
Crust
What affect did the young moon have on Earth
It created violent storms in the ocean because of its gravitational force
What formed on the surface of Earth
Volcanos
What did the Volcanos allow to emerge from the oceans
Volcanic islands
What gas mostly made up the atmosphere of the young Earth
Carbon Dioxide
Meteors again bombarded the Earth, dissolve and bring what from outer space
Minerals and heavy elements
Stromatolites release what gas into the ocean?
Oxygen
How did oxygen get into our atmosphere?
Dissolved oxygen in the ocean rose to the surface and dissipated (spread out) into Earth’s atmosphere
What was the name of the super continent?
Rowdinia
What is the driving force that splits the super continent?
Heat from inside the Earth
Why isn’t the sun’s heat trapped inside the planet’s atmosphere?
There is no carbon dioxide to trap the sun’s radiation (heat)
What is the nickname of Earth during this ice age?
Snow Ball Earth – the longest and coldest ice age of Earth’s history
What releases the Earth from this very long frozen period?
Volcanic activity
What oxygen-rich chemical does the chemical reaction between ultraviolet light and ice make?
Hydrogen Peroxide – released large amounts of oxygen
What did primitive bacteria evolve into?
Multicellular Bacteria (trilobites)