31 terms

# Hug PHCA CHAPTER 1 - all sections

Physical Science Concepts in action Chapter 1
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branches of Science
1- Physical Science
2- Earth and Space Science
3- Life Science
physics
study of matter and energy
science
the methods you use to find out about something
KEY NOTE: Science begins with curiosity and often ends with discovery
technology
Ways to solve practical problems

EXAMPLES of technology (updating inventions)
Little house on the prairie used a wood burning stove, my mom used an oven, we now have microwaves.
controlled experiment
1- an experiment where only one variable (the manipulated variable) is changed on purpose at a time
2- when the responding variable is observed for changes, all other variables are kept the same or controlled
hypothesis
is a proposed answer to a question
manipulated variable
also called the independent variable. A variable that you cause to change during an experiment in order to see its effect or change on something else.
model
1- this makes it easier to understand something that might just be too difficult to observe otherwise
EXAMPLE: If you got lost in a city you could use a street map .
observation
information gathered by using your senses
Senses: Seeing, Smelling, Touching, Hearing, Tasting
responding variable
also called the dependent variable. A variable that changes because of the manipulated variable. The change is measured by the experimenter.
scientific law
a statement that describes a pattern observed in nature
"the law of gravity"
Scientific method
this is an organized plan scientists use to get, organize and communicate information
scientific theory
1- this is an explanation of an experiment that has been run many times.
2- once a hypothesis is supported in repeated experiments, scientists can start to develop it.
accuracy
being as close as possible to the known value. If the known value is 12.01, then 12.02 would be more_____________ than 12.08.
density
the ratio of an object's mass to its volume
grams/cubic centimeter
equals mass divided by volume
length
the straight line distance between two points. The metric base unit is the meter
mass
the quantity of matter in an object or sample
base unit is the gram
precision
an EXACT way to measure
EXAMPLE: a digital clock read to the 100th of a second is more exact than a regular clock with hands.
scientific notation
1- this is the way of expressing a very large or small value by using a number between 1 and 10, multiplied by 10 to an exponent.
EXAMPLE: 120,000,000 = 1.210 to the 8 power and .0012 is 1.210 to the negative 3 power
SI (International System of Units)
Scientists use a system of measuring units that is based on the number 10
thermometer
an instrument that measures temperature
volume
the amount of space an object takes up
base unit is the Liter for liquids or can be a cubic length
communicating data
Scientists tell others there results by:
a) writing in a scientific journal
b) speaking at conferences
direct proportion
a relationship between 2 variables in which their ratio is constant and Y changes in the same direction as X. X goes up, so does Y
inverse proportion
An inverse proportion is one in which the product of the two variables is constant and X and Y move in different directions.
line graphs
a graph that is useful to show changes that occur in related variables. The independent variable is on the X and the dependent on the Y.
organizing data
1- Scientists organize data by using
tables and graphs

EXAMPLES:
a) data tables
b) line graphs
c) bar graphs
d) circle graphs
peer review
scientists examine other scientists work
slope
On the line graph, the ratio of the change in the y-variable to the corresponding change in the x-variable

1- rise/run = change in y / change in x,
2- The steepness of a line on a graph
Kelvin Scale
Starts at absolute zero and water freezes at 273 degrees.
Celsius Scale
Water freezes at 0 on this scale and boils at 100 degrees on this scale. Fahrenheit can be converted to this scale using C=.57(F-32)