Physics!
Science:
Science is the understanding of the behavior of nature based on observations, experiments, models and testing. Science is not merely a body of knowledge but a methodology by which we try to understand the nature and how it behaves.
Hypothesis/Law/Theory:
The words Hypothesis, Law and Theory are three different types of statements about natural phenomena. Hypothesis is a statement that attempts to explain a set of facts that forms the basis for an experiment that is designed to test whether the hypothesis is true or not. Laws reflect scientific knowledge that experiments have repeatedly verified and never proven wrong and their accuracy does not change when new theories are worked out. Theory accounts for a wider variety of events than a law does. Theory in science is an explanation of an aspect of the natural world that can be repeatedly tested with scientific method, and withstands rigorous scrutiny and embody scientific knowledge. The strength of a scientific theory is related to the diversity of phenomena it can explain and its simplicity. Here is a simple example to describe all of these 3 words Hypothesis/Law/Theory: Suppose Cindy's room is a mess. Your hypothesis is that Cindy makes the room messy. You can test this hypothesis with an experiment. Clean up the room and see if it becomes messy again when Cindy returns to her room. If the room remains clean, then your hypothesis is wrong, but if the room becomes messy again then your hypothesis is right and becomes the Law titled "Cindy's Mess Law" stating that Cindy always makes the room messy whenever she comes into her room. Laws have power to predict what will happen under the conditions those apply to. So, "Cindy's Mess Law" predicts that the room will be messy anytime Cindy is in her room. Now if people notice that it becomes messy not only when Cindy goes into her room, but it becomes messy everywhere Cindy goes. So, it becomes "Cindy's Mess Theory" and it can be tested by taking Cindy to some places that she has not been before, like a friend's house, in the classroom, a hotel room etc and she makes those places messy everywhere she goes. This is "Cindy's Mess Theory".
Scientific Notation:
Scientific notation is a method of writing a big number in a small form with exponents by eliminating many zeros. Here is an example: 5,000, 000,000 can be written in scientific notation as 5 x 109.
accuracy
the degree to which a measured value agrees with correct value for that measurement
approximation
an estimated value based on prior experience and reasoning
classical physics
physics that was developed from the Renaissance to the end of the 19th century
conversion factor
a ratio expressing how many of one unit are equal to another unit
derived units
units that can be calculated using algebraic combinations of the fundamental units
English units
system of measurement used in the United States; includes units of measurement such as feet, gallons, and pounds
fundamental units
units that can only be expressed relative to the procedure used to measure them
kilogram
the SI unit for mass, abbreviated (kg)
law
a description, using concise language or a mathematical formula, a generalized pattern in nature that is supported by scientific evidence and repeated experiments
meter
the SI unit for length, abbreviated (m)
method of adding percents
the percent uncertainty in a quantity calculated by multiplication or division is the sum of the percent uncertainties in the items used to make the calculation
metric system
a system in which values can be calculated in factors of 10
model
representation of something that is often too difficult (or impossible) to display directly
modern physics
the study of relativity, quantum mechanics, or both
order of magnitude
refers to the size of a quantity as it relates to a power of 10
percent uncertainty
the ratio of the uncertainty of a measurement to the measured value, expressed as a percentage
physical quantity
a characteristic or property of an object that can be measured or calculated from other measurements
physics
the science concerned with describing the interactions of energy, matter, space, and time; it is especially interested in what fundamental mechanisms underlie every phenomenon
precision
the degree to which repeated measurements agree with each other
quantum mechanics
the study of objects smaller than can be seen with a microscope
relativity
the study of objects moving at speeds greater than about 1% of the speed of light, or of objects being affected by a strong gravitational field
scientific method
a method that typically begins with an observation and question that the scientist will research; next, the scientist typically performs some research about the topic and then devises a hypothesis; then, the scientist will test the hypothesis by performing an experiment; finally, the scientist analyzes the results of the experiment and draws a conclusion
second
the SI unit for time, abbreviated (s)
SI units
the international system of units that scientists in most countries have agreed to use; includes units such as meters, liters, and grams
significant figures
express the precision of a measuring tool used to measure a value
theory
an explanation for patterns in nature that is supported by scientific evidence and verified multiple times by various groups of researchers
uncertainty
a quantitative measure of how much your measured values deviate from a standard or expected value
units
a standard used for expressing and comparing measurements
Chapter-2: Kinematics (One Dimensional Motion)
acceleration
the rate of change in velocity; the change in velocity over time
acceleration due to gravity
acceleration of an object as a result of gravity
average acceleration
the change in velocity divided by the time over which it changes
average speed
distance traveled divided by time during which motion occurs
average velocity
displacement divided by time over which displacement occurs
deceleration
acceleration in the direction opposite to velocity; acceleration that results in a decrease in velocity
dependent variable
the variable that is being measured; usually plotted along the y-axis
displacement
the change in position of an object
distance
the magnitude of displacement between two positions
distance traveled
the total length of the path traveled between two positions
elapsed time
the difference between the ending time and beginning time
free-fall
the state of movement that results from gravitational force only
independent variable
the variable that the dependent variable is measured with respect to; usually plotted along the x-axis
instantaneous acceleration
acceleration at a specific point in time
instantaneous speed
magnitude of the instantaneous velocity
instantaneous velocity
velocity at a specific instant, or the average velocity over an infinitesimal time interval
kinematics
the study of motion without considering its causes
model
simplified description that contains only those elements necessary to describe the physics of a physical situation
position
the location of an object at a particular time
scalar
a quantity that is described by magnitude, but not direction
slope
the difference in y-value (the rise) divided by the difference in x-value (the run) of two points on a straight line
time
change, or the interval over which change occurs
vector
a quantity that is described by both magnitude and direction
y-intercept
the y-value when x= 0, or when the graph crosses the y-axis
Chapter-3: Kinematics (Two Dimensional Motion)
air resistance
a frictional force that slows the motion of objects as they travel through the air; when solving basic physics problems, air resistance is assumed to be zero
analytical method
the method of determining the magnitude and direction of a resultant vector using the Pythagorean theorem and trigonometric identities
classical relativity
the study of relative velocities in situations where speeds are less than about 1% of the speed of light—that is, less than 3000 km/s
commutative
refers to the interchangeability of order in a function; vector addition is commutative because the order in which vectors are added together does not affect the final sum
component (of a 2-d vector)
a piece of a vector that points in either the vertical or the horizontal direction; every 2-d vector can be expressed as a sum of two vertical and horizontal vector components
direction (of a vector)
the orientation of a vector in space
head (of a vector)
the end point of a vector; the location of the tip of the vector’s arrowhead; also referred to as the “tip”
head-to-tail method
a method of adding vectors in which the tail of each vector is placed at the head of the previous vector
kinematics
the study of motion without regard to mass or force
magnitude (of a vector)
the length or size of a vector; magnitude is a scalar quantity
motion
displacement of an object as a function of time
projectile
an object that travels through the air and experiences only acceleration due to gravity
projectile motion
the motion of an object that is subject only to the acceleration of gravity
range
the maximum horizontal distance that a projectile travels
relative velocity
the velocity of an object as observed from a particular reference frame
relativity
the study of how different observers moving relative to each other measure the same phenomenon
resultant
the sum of two or more vectors
resultant vector
the vector sum of two or more vectors
scalar
a quantity with magnitude but no direction
tail
the start point of a vector; opposite to the head or tip of the arrow
trajectory
the path of a projectile through the air
vector
a quantity that has both magnitude and direction; an arrow used to represent quantities with both magnitude and direction
vector addition
the rules that apply to adding vectors together
velocity
speed in a given direction