Physical science test Flashcards
Law of force and acceleration
The acceleration of an object is decedent upon two variables
Law of Inertia
An object at rest stay at rest and object in motion stay in motion unless acted on by outside force
Law of action/reaction
For every action there is an equal and opposite reaction
How can newtons law apply in a car crash?
Third law applies
When a car hits with the same force as the other car action and reaction occurs
Which of newtons law applies to the rocks that gets stuck while the other plate is subducting into the mantle?
Acceleration
Which law causes the land to bulge up above the subducting plate?
Action and force
Which law causes tsunami to occur when earth quakes take place in the water?
Law of inertia
1st law
- only force has the ability to change motion
- net force determine how an object moves
- change in motion comes from unbalanced forces
- Inertia is the property of an object that resists changes in motion
2nd law
- Acceleration is the result of unbalanced forces
- A large force equal a larger acceleration
- Acceleration is inversely proportional to mass
- Force and motion comets through acceleration
- Acceleration is proportional to force
- Net force affects motion
- Formula : force divided by mass
3rd law
Action and reaction is equal in force More mass result in less acceleration D=MV Force only comes in action (action pair) Momentum=mass
What are variables of motion?
The variable of motions are
- position
- velocity
- speed
Why is friction between moving parts of machines undesirable?
It waste energy that could otherwise be used to perform work, make heat!
What do we do to reduce that friction?
applying lubricant such as oil
An example of motion
Rolling down a hill
An example of simple movement
Walking in a line
An example of complex movement
A ball being thrown in the air
Position
Where an object is located
Speed
Precisely how fast an object is moving
Formula:Distance/Time
Acceleration
Precisely how fast an objects speed is changing
Distance
Velocity/time
Time
Distance / Speed
Exact number
Any number obtain by counting or given by definition
Approximate number
Any number obtain by a process of measurement
Accuracy of an approximate number
Number is judge by number of significant digits
Precision of an approximate number
Numbers refers to the decimal position of the significant digit furthest to the right
Significant digits
Digits that have meaning relative to the measuring process used to obtain them
5 rules governing which digits of an approximate numbers are significant
- Nonzero digits
- Zeros that are preceded and followed by significant digits
- Final zeros to the right on the right of decimal point
- Final zero on a whole number are not significant
- If no digits lefts of the decimal point (zeros between the decently point and the first digit are not significant
Example of significant digits
14.24
.0036
14.0024
7001
- 9000
- 03600
Statement: Hawaii is 2400 west of LA
Distance: miles between two cities is 20
4 significant digits (1) 2 significant digits (1&5) 6 significant digits (3) 4 significant digits (2) 5 significant digits (3) 4 significant digits (1&5) 2 significant digits (4) 2 significant digits (4)
Rounding to indicate place value
Digits on the right less than 5, retain the place value
Digits on the right greater than 5 or equal, add 1 to the digits
Eliminate all digits to the right
- 57834 nearest hundredths
- 58 (2)
37.50 nearest unit
38 (2)
- 0031 nearest thousandth
- 003 (1)
Adding and subtracting approximate numbers
Express result with the precision of the least precise number
Multiplying and dividing approximate number
Express result to the accuracy of the least accurate number
Taking the root of an approximate number
Express result to the accuracy of the number
Rounding before and after calculation
Before calculation all numbers except the least precise or the least accurate maybe rounded to one place beyond that of the least precise or least accurate
Exact number in a calculation
The accuracy of the result is limited only be the approximate numbers involved
Qualitative measurement
Measurement that cannot be measured in numbers
Quantitative measurement
Where numbers are used to measure changes
Accurate
Quality of being exact
Precision
The state of being precise
Calibration
To determine, check the graduation of instrument giving quantitive measurement
International system of unit
Accepted system of physical unit
Mass
A body of matter
Weight
The amount or quantity of heaviness or mass
Meniscus
The crescent or a crescent shape body
Different kind of forces
Contact force Normal force Friction Elastic force Electrostatic force Magnetic force Gravity Strong force Weak force
Forces are balances or unbalanced
Balanced force always change the motion of the object
Unbalanced force never change the motion of the object
You can tell if a force is balanced or unbalanced by if the object change motion
What is force?
Push or pull
Unbalanced or balances
Direction and magnitude
Measured in newtons
Chemistry measurement unit metric prefixes table
Great Mighty King Henry Die By Drinking Chocolate Milk Monday Night
Giga G 1,000,000,000 1,000,000,000/1 10^9 1Gm=1,000,000,000 m
Mega M 1,000,000 1,000,000/1 1,000,000^6 1Mm=1,000,000 m
Kilo k 1000 1000/1 10^3 1 km = 1000 meter
Hecto
h
100
100/1
10^2
1 hm = 100 m
Deka
da
10
10/1
10^1
1 dam = 10 meter
Basic unit N/a Seconds, liter, meter, grams 1 1/1 10^0 1m = 1 meters
Deci D 0.1 1/100 10^-2
Centi
Milli
Micro
Nano
Observation
Gathering of information through the use of our 5 senses
Because senses are limited, instruments were developed
Microscope, telescope, cameras
2 type of observations
Quantitative
Measuring and counting
5 petals
Qualitative
Describing
The flower is red
Conclusion from observation
Inferences
Hypothesis
Inference
Reasonable conclusion based on observation
The school is having a scheduled monthly drill
The student is in trouble
Hypothesis
Idea taken from observation that is testable
Forms:
A question
Conditional statement
An if-than question
Independent variable
The variable controlled by experimenter
A daisy will grow faster if water more frequently
Independent variable is how often the daisy is watered
Dependent variable
The variable measured as a result of changing the independent variable
A daisy will grow if watered more frequently
The independent variable is growth of the daisy
What should a strong hypothesis should always be?
Clear
Simpler
Measurable
Replicable
Theory
An explanation for a large body of knowledge
Natural selection theory
Cell theory
Law
Can only explain phenomena, but cannot tell why it happens
Law of segregation
Alleles controlling a trait are separated during meiosis
Law of independent assortment
Homologous chromosomes separate independently of other homologous chromosomes
A scientific theory is
Same as hypothesis
Which is strongest hypothesis?
Deciduous trees loses their leaves in the autumn in response to changing temperatures
A scientist is testing the effect of a chemical on an orange grove yield. One orange grove has the chemical applied and another does not. The number of oranges harvested from each grove is then counted. What is the independent variable of this experiment and why?
Number of oranges harvested because you won’t know the out come.
Does the plant food, Super grow, work as well as its commercial claims?
If I feed super grow to the plant, then it will respond to the chemical hast as the commercial claims!
Blade length
The measure of the blade from end to end
Blade pitch
The angle of the blade on the rotor
Blade twist
A blade twist build into the blade to equalize the lift
Tip shape
The taper of the blade tip
Airfoil shape
The curved shape of the blade
Turbine height
The height of the turbine when installed at the top of the tower
3m material
Performance materials added to the blade in order to increase lifespan and efficiency
Type of thermometer
Fahrenheit
Celsius
Absolute zero
Scales
Kelvin scale
Digital
Liquid crystal
What is matter?
430 BCE
Greek philosopher-matter were made out of tiny particle called atom
1803
Atoms but lacked proof
1827
Brown-tiny grains in water making the brownish motion which is a jerky irregular motion
1905
Albert E. Brownian motion caused by collusion between visible particle like pollen grains and smaller visible partial
Testable questions
Specific
Measurable
Not opinion
Suggest an experiment
Controlled experiment
Independent variable
You change
Dependent variable
Data
Control
Comparison group
Group that does not received the standard treatment
Controlled variable
Things kept same between experimental group
Procedures designs to make sure that only the independent variable is changing between experimental group
Table and graph must have
Title describing the experiment
Dependent vs independent
Independent variable on the x axis
Dependent variable on y axis
Scientist believe the universe follows a set of rules called
Natural law
Learning about science by asking question is called
Inquiry
Scientific evidence must be
Objective,which mean evidence should describe only what happens as exactly as possible
Repeatable
Include numbers, graph, words, pictures, sound recording, or other information
Scientific evidence must be communicated clearly with no room for misunderstanding
Scientific theory
Attempt to describe a natural law
2 things can happen with new evidence
The current theory correctly explains the new idea or current theory does not explain the new evidence so a new or improved theory is waiting to be discovered
Goal of experiment
Understand the relationship between variable
Simple ideal experiment only
One variable is changed at a time
Trial
Each time you run a test
Experimental technique
How you actually do the experiment
Procedure
Collection of all the techniques you use to do an experiment
What is the engineering cycle
Design a prototype
Build a prototype
Test a prototype
Evaluating a prototype
Conceptual design
Your ideas
Prototype
A working model of a design that can be tested to see if it works
Units
Show relationships between independent and dependent variable
Bar graph
Compares categories of data
X axis - categories
Y axis - numerical data
Line graph
Used for data that changes over time
Connect dot to dot
X axis - Time
Y axis - numerical data
Pie chart
Compare parts of a whole
Written as a percentage
X Y scatter plot
Used to determine the relationship between two variable
Both axis have numerical data graphed on a scale
Y axis - dependent variable
X axis - independent variable
Line may be curves or straight
Volume
The amount of space the object takes up
Meters cubed
Displacement
Finding the volume of an irregular shape
Efficiency
Of a Machines is the ration of usable output work divided by total input work
Expressed in percentage
Power
The rate at which work is done
P=W/T
One watts
1 joules
Work input
Work or energy supplies to process or machines
Work output
The work or energy comes out of the process or machines
Work
Form of energy you either use or get when a force is applied over a distance
W=F/D
Force times distance
Potential energy
Amount of work it can do
Mxgxh
Kinetic energy
The amount of work the object can do exerting force when stop
1/2 MV squared
Use find know
Acceleration
Force divided by mass
Force
Mass times acceleration
Mass
Force divided by mass
Density
How much mass is in a given of a material
Density
Mass divided by volume
Volume
Mass divided by density
Mass
Density x volume
