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