Post on 26-Dec-2015
transcript
Earth Science is the study of our planet (Terra Three), its
changing systems, and its position in the Universe.
I. Earth Science
Earth Science investigates and tries to answer questions like:
I. Why do we have seasons? II.How can we predict the weather? III.Why are stars grouped and move
together in the night sky? IV.What forms a landscape?
Earth Science covers many different disciplines (or branches of scientific study) such as:Geology - the study of our planet (it’s
structure, crust, composition, etc.). Meteorology - the study of the atmosphere; weather and climate.Astronomy - the study of the Earth's motions and objects in space.Oceanography - the study of the oceans.
The study of earth science divides the Earth up into three main parts:
Lithosphere: The solid Earth
Hydrosphere: All the water on Earth
Atmosphere: All the gases surrounding the Earth
Why is earth science important?
Forecast potential disasters and help save lives and property.Gain access to the Earth’s resources.Protect the environment.
The Pathways to Discovery: The
Scientific MethodThe scientific method is a guide to
scientific problem solving.
State the Problem
ObservationAn observation is an interaction of one or more of the senses (sight,hearing, touch, taste or smell) with part of the environment.Care must be exercised when using the senses to prevent injury. (Taste is rarely used to prevent poisoning).Instruments are devices invented to extend our senses beyond their normal limits.
Gather InformationMeasurement
A measurement is a means of expressing an observation with greater precision.
Basic dimensional quantities include...• 1. Length – the distance between two
points.• 2. Mass – the amount matter in an
object. Mass is the number of things (atoms, etc) an object has.
**Weight is a force caused by a gravitational attraction.***
Weight ≠ Mass
• 3. Time – a measurement that allows us to determine "when" an event occurred.
• 4. Temperature – a measurement of the average internal energy of an object.
Classification A classification is a grouping of similarly observed properties of objects or events to aid studying a subject.
Classification of our solar system
Jupiter Saturn Neptune Uranus
G as Planets
M ercury Venus Earth M ars Pluto
T errestria l (land)
Planets
Form a hypothesis
Hypothesis: a possible solution or explanation of a problem.
Test the HypothesisA hypothesis is tested by experimentation.Each experiment has at least two variables.
Dependent variable: Data that you are measuring in your experiment. • Vertical axis of graph
Independent variable: The data that you know ahead of time.• Horizontal axis of graph
State a Conclusion
Inference. An inference is an interpretation (or conclusion) based on our observations, and is only as reliable as our best observations.
Inferences may or may not be correct.
Basic dimensional units (length, mass, time, temperature) can be combined to produced additional measurements that can assist in making observations and classifying properties of objects.
1. area is a length x width2. volume – the amount of space an object contains or occupies.• volume is Length x Width x Height.
3. speed – the distance an object covers in a given period of time.
Scientific Notation Scientific notation is a method for expressing very large numbers in the form of small numbers which scientists work with. A number written in scientific notation is written in the form M x 10n, where M is a number between 1 and 10 (but not 10), and n is the power it is raised to(how many places the decimal point was moved).
Thus the number 254.3 is written as 2.543 x 102.
Here’s a closer look of how it works.4156.2
First we want to make this into a number in between 1-10.• 4.1562• Remember how
many places the decimal point was moved
• Now plug into formula Mx10n
4.1562 x 103
That’s it!
Now we can go in reverse to…3.12 x 101
First we want to move the decimal place back.• 31.2• You’re done!• REMEMBER if the
exponent is positive, move in a positive direction. If the exponent is negative, move in the negative direction.
kilo-
hecto-
deco-
deci-
There are several Metric Prefixes that you must know:
centi-milli-
1000 100
10
0.1
0.001
0.01
*metric unit*
Here’s a way to remember the order.
KidsHateDadMomDoesn’t CareMuch
Practice
1.) 225.3m=_____km
2.) 32.1cm=_____mm
3.) 0.859cm=_____m
4.) 0.206km=_____mm
B. Error
No measurement is perfect! Measurements are limited by imperfection of the senses and instruments, and human error.
Percent Deviation (Percent Error)
See front page of Ref. Table% Deviation = (Accepted –Measured) x 100(Accepted)
Ex: measured mass = 36gaccepted mass = 40g
% Deviation = (40g – 36g) x 10040g
% Deviation = 4g x 10040g
% Deviation = 10%
C. DensityDensity is the concentration of matter an
object has. (Front page of Reference Table)
Density = Mass Volume
Density is affected by anything that changes the volume an object occupies.
Temperature & Pressure
Temperature
causes most objects to change their volume.
As temperature increases, volume increases (most substances expand when heated),cooling causes volume to decrease.
Direct relationship
Temperature
Volume
Water is the exception!!!
As temperature increases, volume decreases.
As temperature decreases, volume increases.
Inverse (Indirect) relationship
Temperature
Volume
Water has its highest density (1.0 g/mL) at 4 oC (36 °F), as water cools its density decreases (opposite normal matter), hence ice floats on liquid water.
Matter that has a density less than 1 g/mL will float in water.
Matter that has a density more than 1 g/mL will sink in water.
Pressure
affects the volume of a substance.
As pressure increases the volume decreases.
Inverse relationship
D. Phases (states) of matter.Matter is normally found in three phases or states, although, there is a fourth phase (state).
The phases are:1. Solid – rigid structure, fixed volume & shape.
(normally an object's highest density).2. Liquid – fixed volume, will assume the shape
of it's container.3. Gas – no fixed structure, expands to fill the
volume and shape of the container it is placed in. (normally an object's lowest density)
4. Plasma – exists in stars, not found on earth.
IV. Nature of change A.Characteristics of change
The Earth's environment is in a constant state of change.
Change can be described as an occurrence of an event.
The event (change in condition of
properties of a substance) can occur over a long period of time or instantaneously.
C. Rate of ChangeThe rate at which change occurs.
Rate of change =Change in field value
Time Most earth processes are slow,
taking sometimes millions of years to evolve.
D. Cyclic Change
Changes that are repetitive in nature, (a repeating pattern). Singular occurring events are said to be non–cyclic.
Cyclic Change
E. Prediction of change When change is cyclic or if a trend can be inferred, a prediction can be made relative to the data. Factors involved in change are called variables. The greater the frequency of observation and/or the fewer the variables involved, the greater the accuracy of the prediction of the change.