Introduction- Physical Science Notes 1
Charles Darwin- theory of natural selection
Natural Selection- the process in which advantageous traits increase the likelihood for survival and become more prevalent in the population.
1) Variation between organisms
2) Some forms of variation are heritable
3) Some forms of variation are better than others
4) Populations grow exponentially
5) Populations can NOT grow exponentially for long
Evolution- Consequence of Natural Selection
Mutation- a change in genetic material which can be passed to an organisms offspring resulting in genetic variability
Selective Advantages- A characteristic of an organism that permits it to produce more offspring.
Process of Science
Why do we use the process of science?
What is the goal of science?
Objective
Subjective
Accurate
Precise
Science is based on observations and testing hypotheses.
What is an observation? What is a hypothesis?
What is reality?
2 types----------------Actual Existence
-----------------Human Judgment
Humans are limited by their perceptions and judgment.
Do facts change?
What does the term proof mean?
There is no such thing as PROOF in science!!!
· Proof implies 100% certainty
· Statistically very hard to achieve
· Human judgment
If proof does not exist what do we use in place of it?
- data indicates
- data suggests
- evidence supports
- evidence suggest
- data supports
Experimental Design
- the process of designing and conducting experiments
Scientific Method
- establish a question
- form hypotheses (Null Hypothesis)
- design experiment
- statistically analyze data and compare results to the Null Hypothesis(HO)
- form conclusion which provides information about universe
Only after repeated testing a hypothesis becomes a theory.
Notes #2 Physical Science Mr. Seegers
Measurements
-why important?
Fundamental Physical Quantities
-length
-mass
-time
Length
- a measurement of space in any direction
Mass
-refers to the amount of matter an object contains
Time
-continuous, forward flowing of events
To use these quantities we need to compare them with a reference or standard unit.
Standard unit
- is a fixed and reproducible value for the purpose of taking measurements
Standard Units for the Metric System
Length=Meter
Mass=Kilogram
Time=Second
Basic Equations for Measurement
Area = (length x width)
Volume V=(Length x Width x Height)
Motion
- if object is undergoing a continual change in position it is motion
- motion is described by length and time
Scalar Quantity
- value that has number and units but NO direction
e.x. 50 km/hr
Vector Quantity
- value that has number and units with direction
e.x. 50 km/hr west
Difference between speed and velocity
- speed is scalar
-velocity is vector (has direction)
Speed = distance/ time
Acceleration = Vf-Vo/t
_______
Vo= initial velocity
Vf= final velocity
t= time
Instantaneous Speed
- velocity at any instant of time
e.x. speedometer in car
Constant downward acceleration is 9.8 m/s2
To calculate the distance a dropped objects travels downward with time use the following
d=1/2 gt2
Notes#3 Physical Science Mr. Seegers
Sir Isaac Newton
- developed the laws of motion and gravitation
Force
- is a quantity that is capable of producing motion or a change in motion
Newtons First Law of Motion
- a body at rest will remain at rest and a body in motion will remain in motion until force is applied
Balanced and Unbalanced Forces
balanced forces
- forces that are equal and opposite
unbalanced
- unequal forces resulting in motion
Inertia
- the natural tendency of an object to remain in a state of rest
Mass
- measure of inertia
- the greater the mass the greater its inertia
Newtons Second Law
-the direction of acceleration is in the direction of the applied net force
- if the net force is doubled the acceleration is doubled
- if the mass is doubled the acceleration is halved
F=ma
Newtons Third Law
-for every force (action), the is an equal and opposite force (reaction)
The correlation between weight and mass
w = mg