Shared Flashcard Set

Details

mid term physical science review GMHS
mid term review
74
Science
8th Grade
01/27/2010

Additional Science Flashcards

 


 

Cards

Term
Pure Science
Definition
Research simply for the sake of research or "the search for new information"
Term
Applied Science (technology)
Definition
involves actually using science to improve the technology around us and ease everyday life
Term
Steps of the scientific method
Definition

1. State the question

2. Collect information

3. Form a hypothesis

4. Test the hypothesis

5. Observe the results

6. Record the data

7. Analyze the data

8. Form a conclusion

Term
Independent (manipulated) variable
Definition
The variable in an experiment that you change. There can only be ONE independent variable.
Term
Dependent (responding) variable
Definition
The factor in an experiment you are measuring as a result of changing the independent variable.
Term
Valid scientific experiment
Definition
  • valid experimental set up
  • valid experimental subjects

(One independent variable, one measurable dependent variable and all other variables kept constant)

Term
Controls
Definition
the group in an experiment that is used as a standard for comparison. In this group no variables get changed.
Term
Constants
Definition
all the other variables in an experiment that remain unchanged
Term
When graphing what do you put of the:
- x-axis
- y-axis
Definition
Independent goes on the x-axis
Dependent goes on the y-axis
Term
Uses of line graphs vs. bar graphs
Definition
line graph- two quantitative variables
bar graph- one qualitative and one quantitative variable
Term
Distance
Definition
Total distance the object has traveled
Term
Displacement
Definition
How far the object is from its original position
Term
velocity
Definition
the amount of distance traveled in a specific amount of time plus a direction (vector quantity) 
Term
Speed
Definition
the amount of distance traveled in a specific amount of time (scalar quantity so abosolute value of velocity)
Term
equation for speed
Definition
s = d/t
Term
acceleration
Definition
the rate of change in an objects velocity
Term
equation of acceleration
Definition
a = (Vf-Vi)/t
Term
what must take place for acceleration to occur
Definition

- change in direction

- speeding up

- slowing down

Term
units for speed, distance and acceleration
Definition

speed- m/s

distance- m

acceleration- m/s2

Term
Force
Definition
the push or pull one object exerts on another
Term

balanced and unbalanced forces??

(still dont really get this one)

Definition

balanced- the net force on the object is 0

unbalanced- the net force on the object is more or less than 0

Term
inertia
Definition
the tendency of objects to resist any change in motion
Term
gravity
Definition
the attractive force of one object on another that exists everywhere that matter exists (holds us down to the earth)
Term
mass
Definition
how much matter an object contains
Term
weight
Definition
the measure of the force of gravity on an objects mass
Term
acceleration due to gravity on earth
Definition
9.8 m/s2
Term
Newton's first law
Definition
An object in motion will stay in motion and an object at rest will stay at rest unless acted upon by an outside force
Term
Newton's second law
Definition
the acceleration of an object is related to the net force acting on it and the mass of the object
Term
Newton's third law
Definition
For every action, there is an equal and opposite reaction
Term
Newton's law of Universal Gravitation
Definition
Any two objects exert a gravitational force of attraction on eachother
Term
terminal velocity
Definition
when an object stops accelerating due to the force of gravity equaling the air resistance because of the increase in velocity as the object falls
Term
air resistance
Definition
the force which air molecules exert upon a moving object
Term
Friction
Definition
a force that opposes motion between two touching surfaces
Term
momentum
Definition

the quantity of motion that an object has because of its mass and velocity

(kgm/s)

Term
Law of conservation of momentum
Definition
the total momentum of a group of objects does not change unless outside forces (usually friction) act upon the objects
Term
energy
Definition
the ability to do work or cause change
Term
1 form of energy
Definition

electrical energy- the energy of charged attraction

(energy we get from a household circuit)

 

Term
2 form of energy
Definition

magnetic energy- the energy of polar attraction

(magnet picking up "magnetic substances)

Term
3 form of energy
Definition

mechanicle energy- the energy of machines doing work

(a turning motor)

Term
4 form of energy
Definition

heat (thermal) energy- the energy of burning calories, usually noticed through changes in temperature

(warming a cup of water until the water undergoes a phase change)

Term
5 form of energy
Definition

light (radiant) energy- the energy radiating from waves

(UV rays from the sun give off light energy)

Term
6 form of energy
Definition

chemical energy- the energy of breaking bonds in chemical reactions

(a battery that turns a chemical reaction inside itself into energy)

Term
7 form of energy
Definition

nuclear energy- the energy of atomic reactions in the nucleus of the atoms

(radioactive decay like at nuclear power plants)

Term

8 form of energy

 

Definition

gravitational energy- the energy from using the pull of gravity

(water from a waterfall)

Term
kinetic energy
Definition
the energy of motion
Term
potential energy
Definition
the energy of position
Term
factors that affect kinetic energy
Definition
mass and velocity
Term
factors that affect potential energy
Definition
mass, gravity and height
Term
law of conservation of energy
Definition
in a closed system, all energy is conserved (the energy is transferred)
Term
work
Definition
the amount of energy required to move an object a certain distance with a specific force
Term
machine
Definition
any device that makes work easier
Term
the six simple machines
Definition

- wheel and axel

- screw

- lever

- pulley

- wedge

- inclined plane

 

Term

mechanicle advantage

(need this one)

Definition
Term
three types of levers
Definition

first class lever- the fulcrum is located in between the resistance arm and the effort arm

second class lever- the resistance is located between the effort force and the fulcrum

third class lever- the effort force is located in between the fulcrum and the resistance

Term
how does work input compare to work output???
Definition
work output will always be less than work input due to friction
Term
waves
Definition
a disturbance that transfers energy
Term
how are waves created
Definition
when a source of energy causes a vibration in a medium
Term
three types of waves
Definition

- longitudinal

- transverse

- surface

Term
four characteristics of waves
Definition

- amplitude

- frequency

- speed

- wavelength

Term
longitudinal waves
Definition
waves whose mediums move the same direction as overall wave travel
Term
transverse
Definition
waves whose mediums travel perpendicualr to overall wave travel
Term
what type of waves are sound waves
Definition
longitudinal
Term
factors that affect the speed of sound
Definition

- elaticity

- density

- temperature

Term
pitch
Definition

how high or low the sound appears to our ears

- affected by frequency

Term
intensity
Definition

how much of a mediums vibrations pass in a given time

- affected by amplitude

Term
reflection
Definition
when a wave hits a surface that it cannot pass through and bounces back
Term
refraction
Definition
the bending of a wave due to change in speed
Term
diffraction
Definition
the bending of waves due to an obstacle in its path
Term
constructive interference
Definition
crests aline with crests and troughs with troughs so amplitudes combine to be greater than the original amplitude
Term
destructive interference
Definition
troughs aline with crests and crests with troughs so amplitudes cancel eacthother out
Term
electromagnetic waves
Definition
waves that carry energy without requiring a medium  are created by changing electrical and magnetic feilds
Term
what type of waves are EM
Definition
transverse
Term
what is the speed of EM waves in a vacuum
Definition
300,000,000 m/s
Supporting users have an ad free experience!