Physical Science Midterm Review
kinetic energy
energy a moving object has because of its motion; determined by the mass and the speed of the object
gravitational potential energy
energy that is due to the gravitational force between objects
elastic potential energy
energy that is stored by compressing or stretching
chemical potential energy
energy that is stored due to chemical bonds
potential energy
energy that is stored due to the interaction between two objects
heat
energy that is transferred between objects due to a temperature difference between these two objects
scientific law
statement about what happens in nature that seems to be true all the time doesn't explain why or why not
Newtons 1st Law (law of inertia)
states than an object in motion stays in motion unless acted upon another force
law of conservation of energy
states that energy cannot be created or destroyed
Second Law of Thermodynamics
states that energy spontaneously spreads from regions of higher concentration to regions of lower concentration
First Law of Thermodynamics
states that if the mechanical energy of a system id constant, the increase in the thermal energy of the system equal the the increase of thermal energy to system and work done
Newton's 2nd Law
states that the acceleration of an object is in the same direction as the net force on the object and that the acceleration equals the net force divided by its mass
law of conservation of momentum
states that the change can be transferred from one object to another but it cannot be created or destroyed
Newton's 3rd Law
states that when one object exerts a force on a second object exerts a force on the first object that is equal in strength and in the opposite direction
thermodynamics
study of the relationship between thermal energy, heat and work
net force
sum of all the forces that are acting on an object
mechanical energy
sum of potential enery and kinetic energy of objects in a system
conduction
transfer of thermal energy by collisions bewtween the particles that make up matter
convection
transfer of thermal energy in a fluid by the movement of warmer and cooler fluid from one place to another
graph
visual display of of information or data
transverse wave
wave in whcih the matter in the medium moves at right angles to the direction of the wave, has crests and troughs
what might a scientist do to communicate scientific results?
write a scientific paper
the scientific process begins with asking questions and .....
making observations
density
mass per unit of volume of a material
medium
matter through which a wave travels
temperature
measure of the kinetic energy off all the particles that make up an object
volume
Amount of space occupied by an object
motion
a change in an object's position in relation to a reference point
independent variable
a factor that, as it changes affects the measure of another variable
thermal insulator
a material through which thermal energy moves more slowly
amplitude
a measure of the size of a wave, related to the energy it carries
node
a point in a standing wave at which the interfering waves always cancel
field
a region of space in which every point has a physical quantity, such as force
wave
a repeating disturbance that transfers energy as it travels through matter or space
longitudinal wave
a wave in which the matter in the medium moves back and forth along the direction that the wave travels
standing wave
a wave pattern that forms when waves of equal wavelength and amplitude but traveling in different directions, continuously interfere with each other, doesn't appear to be traveling
mechanical wave
a wave that can only travel through water
centripetal acceleration
acceleration of an object toward the center of a curved or circular path
mass
amount of matter in an object
matter
anything that takes up space and has mass
technology
application of science to benefit people
gravity
attractive force between two objects that depend on the masses of the objects and the distance between them
a conclusion at the end of a scientific investigation...
can be that your results either support or do not support your hypothesis
model
can be used to represent an idea, object or event that is too big, too small, too complex, or too dangerous to observe or test directly
compression
denser region of a longitudinal wave
freefall
describes the fall of an object on which only the force of gravity is working
heat engine
device that converts some thermal energy to mechanical energy
machine
device that makes doing work easier by increasing the force applied to an object, changing the direction of an applied force or increasing the distance over which a force can be applied
solar collector (solar panel)
device used in an active solar heating system that transforms radiant energy into thermal energy
speed
distance an object travels per one unit of time
displacement
distance and direction of an object's change in a position from the starting point
wavelength
distance between one point on a wave and the nearest point just like it
Aft collecting data, you can analyze it by ..........
doing calculations and organizing the results into graphs
standard
exact, agreed-upon quantity used for comparison
theory
explanation for things or events based on knowledge gained from many observations and investigations
dependent variable
factor that changes as a result of changes in toereh variables
centripetal force
force that is directed toward the center of a curved or circular path
air resistance
force that opposes the motion of objects that move though the air
friction
force that opposes the sliding motion between 2 touching surfaces
Susan said, "If I fertilize my geranium plants, they will blossom."
form a hypothesis
Once you've asked questions and made observations, you are ready to...
from a hypothesis and test it
weight
gravitational force exerted on an object
society
group of people that share similar values and beliefs
internal combustion engine
heat engine that burns fuel inside the engine in chambers or cylinders
crest
highest point on a transverse wave
constant
in an experiment, a variable that does not change
SI
international System of Units- the improved, universally accepted version of the metric system that is based on multiples of 10 and includes the meter(m), Liter(L), and kilogram(kg)
trough
lowest point on a transverse wave
compound machine
machine that is a combo of two or more simple machines
simple machine
machine that works with only one movement; examples include: lever, pulley, inclined plane, screw, wedge, wheel and axel
bias
occurs when a scientist's expectations change how the results of an experiment are viewed
experiment
organized procedure for testing a hypothesis; tests the effect of one thing or another under controlled conditions
Scientific Methods
pattern of investigation procedures that can include stating a problem, forming a hypothesis, researching and gathering information, testing a hypothesis, analyzing data, draw conclusions, and communicating results
hypothesis
possible explanation for a problem using what is known and observed
momentum
property of a moving object that equals its mass times its velocity
force
push or pull exerted on an object
variable
quantity changed that have more than a single value, can cause a change in the results of an experiment
power
rate at which energy is converted; measured in watts
acceleration
rate of change of velocity can be calculated by dividing the change in velocity byb the time it takes to occur
mechanical advantage
ratio of the output force exerted by a machine to the input force applied to the machine
efficiency
ratio of the output work done by the machine to the input work done on the machine, expressed as a percentage
Hudson saw bats catching insects after dark. He asked, "How do bats find insects in the dark?"
recognize a problem
system
region or set of regions around which a boundary can be defined
control
standard used for comparison of test results in an experiment
Ann grew bacteria from the mouth on special plates in the lab. She placed drops on different mouthwashes on bacteria on each plate.
test the hypothesis with an experiment
energy
the ability to cause change measured in joules
specific heat
the amount of heat needed to raise the temperature of a 1 kilogram of material 1 degree Celcius
period
the amount of time it takes 1 wavelength to pass a fixed point; expressed in seconds1`
refraction
the bending of a wave caused by a change in its speed as it travels from one medium to another
diffraction
the bending of waves around an obstacle; can also occur when waves pass through a narrow opening
rarefaction
the less dense region of a longitudinal wave
terminal velocity
the maximum speed of an object will reach when fallong though a substance such as air
frequency
the number of wavelengths that pass a fixed point each seconf; expressed in Hertz (Hz)
resonance
the process by which an object is made to vibrate by absorbing energy at its natural frequencies
interference
the process of two or more waves overlapping and combining to form a new wave
velocity
the speed and direction of a moving object
thermal energy
the sum of kinetic and potential energy of the particles that make up an object
inertia
the tendency of an object to resist any change in its motion
radiation
transfer of energy by electromagnetic waves
work
transfer of energy when a force is applied over a distance; measured in joules