114 CERT EXAM

Law of Conservation of Mass

equal atoms in the equation; matter and energy are conserved, in a closed system

kinetic energy

moving

potential energy

stored energy

Mechanical Energy (ME) =

kinetic energy + potential energy

3 components of a circuit

1. path to conduct: usually made with wire

2. voltage source: the “push” to produce current (ex: batteries or outlet)

3. Resistor: opposes flow, resistance measured in ohms (ex, light bulb or motor)

heat vs temperature

Substance has thermal energy but transfers hear

1st Law of Thermodynamics

Energy cannot be created or destroyed, only transformed from one form to another.

work done BY the system…

…reduces internal energy

work done ON the system…

…increases internal energy

calculate change in internal energy

△U=Q (heat added) - W (work done)

2nd Law of Thermodynamics

• heat flows from hot to cold

• Entropy ( measure of disorder) increases

Exothermic

• lose energy

• bond making

• combustion of fuel

Endothermic

• gain energy

• bond breaking

• absorption of heat

closed system

no matter enters or leaves the system

current =

voltage/resistance

• flow of electric charge

high voltage =

=high current

short circuits

electricity w/ no resistance is dangerous

series circuits

single path & require all elements to work

• shares battery voltage

  • more bulbs = more resistance = less current = less light

Parallel Circuits

more than one path; not all elements need to work

• each look receives full battery

Fusion

lights elements join to make heavier elements

Fission

Elements break into lighter elements

Simple Machines

1. change amt of force

2. change direction

3. change distance

ideal simple machines are…

…frictionless

input=

=effort (applied)

output=

=load (actual force that is moved)

actual simple machines are…

…have friction, input> output and produces heat

total surface area

find the area of EACH face… think of finding the area of a net

displacement

straight-line distance and direction

Displacement vs. Distance

Displacement < or = to distance

Speed

how fast position changes

avg. speed = distance/ time

Velocity

object speed and direction

avg velocity = displacement/time

acceleration

quick change in velocity

avg accel. = △velocity / time

Newton’s 1st Law of Motion

Inertia - resist change in motion, object remain at rest until moved

Newton’s 2nd Law of Motion

Force = mass x accel.; more force = more accel.

Newton’s 3rd Law of Motion

Equal and Opposite Reaction

gravity

forces of mass pull on one another (weak)

Scientific Method

1. identify problem

2. observations

3. hypothesis

4. experiment

5. data

6. draw conclusion

7. reform hypothesis & draw new experiment

Antoine Lavosier

Modern Chemistry

Single-Variable Investigation

researcher makes before and after application of interest

Correlational Research

scientist may study two variables, but does not control the rest of the conditions of the study

Quasi-experimental

scientists studies the effects of an independent variable but chooses the experimental groups rather than assigning them randomly

Independent Variable

(x-axis) manipulated

Dependent Variable

(y-axis) measured effect

Axis of Symmetry=

= x-value of the vertex

Vertical Transformation

y=fx + c

Horizontal Transformation

y=f(x+c)

Vertical Reflection (over y)

y = - f(x)

Horizontal Reflection

y= f( -x)

Vertical Stretch

y = c x f(x); c>1

Vertical Shrink

y = c x f(x); 0<c<1

Wave

energy that moves from one place to another

period

time it takes to complete one full wave cycle(measure in time)

Wavelength

length of one complete wave cycle (measure in distance)

Frequency

The number of full cycles that happen each second

wave speed=

= wavelength x frequency

wave period=

1/frequency

amplitude

distance from the center of the wave

intensity

amount of energy transported by the wave (measured in decibels)

loudness

Sound depends on human perception of the intensity

threshold of hearing

sound of 0 decibels, softest sound human can hear

threshold of pain

120 decibels of sound

pitch

high or low, the notes sound

What type pf lense does a telescope use?

convex (refracts)