|
1 a]
What is an hypothesis?
A statement or set of statements that helps to order or unify a set of facts.
Example: the Kinetic Theory of Heat explains how heat moves from a hot to cold
object & not the reverse, and why rubbing two things together produces heat.
b] What is a law?
A cause and effect relationship, without an explanation.
c] Give an example of a law.
Ex#1: Force of Gravity = a attractive force between any two objects.
Fg = GxMass 1 x Mass 2 .
(Distance between centers of gravity)2
d] Define theory: a tested set of statements that explains and predicts
an outcome.
e] State an example of a theory
Ex#1: Spontaneous Generation: certain forms of life (flies, worms, mice) can
spontaneously grew out of non-living things such as mud or decaying flesh.
Ex#2: Darwin’s theory of evolution. Creatures that adapt to changes in their
environment will have better chances of survival, and be less likely to become
extinct, than those who don’t.
Ex#3: Kinetic theory of gases. All matter is in constant motion, with
inelastic collisions, etc.
f] How does a hypothesis become a law?
If, after many tests, no one can demonstrate the hypothesis incorrect it is
accepted as a law.
g] State and example how a law was proven incorrect.
#1: Caloric theory explained how things became hotter and cooler.
Caloric was a fluid that flowed from hot things to cool. It could not explain
why rubbing two rough surfaces together made them warmer. Kinetic theory said
that heat is a form of energy that is transferred when fast-moving particles hit
other.
#2--The law of gravity once was: "Whatever goes up must come down."
Newton developed a theory that predicted the measured orbits of the planets
which are up and don't come down. His law is: Fg = GM1M2/d2
#3: The Law of Conservation of Mass & Energy once was: "Matter and energy
cannot be created or destroyed." They investigated nuclear reactions and found
the E = mc2 , or The energy created in a nuclear reaction = the mass
destroyed x speed of light squared.
e] Define and give an example of a theory.
A theory is an explanation for a cause and effect relationship.
Ex #1: Kinetic Theory of Gases: pressure is caused by perfectly elastic
collisions of gas molecules with the container walls.
Ex #2: Theory of Evolution: complex organisms develop from simpler ones.
Ex #3: Spontaneous Generation: flies emerge spontaneously (without outside
aid) from rotting meat.
2 LABEL
AS: DIRECT, INVERSE, SQUARE, or SQUARE ROOT VARIATION
a] Y = aX2 + b SQUARE
c] Y = a/X + b INVERSE
b] Y = aX + b DIRECT
d] Y = a√X + b SQUARE
ROOT
3
SKETCH & LABEL THE GRAPH FOR EACH VARIATION.
4
DESCRIPTIONS: LABEL AS DIRECT, INVERSE, SQUARE, or SQUARE ROOT
a] IF THE CAUSE (X) DOUBLES (↑ 2x)
THEN THE EFFECT (Y) HALVES (↓BY 1/2)
INVERSE
b] IF THE CAUSE (X) TRIPPLES (↑ 3x)
THEN THE EFFECT (Y) INCREASES 9x
SQUARE
c] IF THE CAUSE (X) DOUBLES (↑ 2x)
THEN THE EFFECT (Y) DOUBLES (↑ 2x)
DIRECT
d] IF THE CAUSE (X) INCREASES 9x THEN THE EFFECT (Y) INCREASES ONLY 3x
SQUARE ROOT
e] IF FORCE INCREASES 2x THEN ACCELERATION INCREASES 2x DIRECT
f] IF PRESSURE ON A GAS INCREASES 2x THEN ITS VOLUME DECREASES 1/2: INVERSE
g] IF SPEED INCREASES 3x THEN FORCE INCREASES 9x
SQUARE
5 WRITE
AS AN EQUATION:
a] IF PRESSURE ON A GAS INCREASES 3x THEN ITS VOLUME DECREASES 1/3
VOLUME = A/PRESSURE
b] IF SPEED INCREASES 4x THEN FORCE INCREASES 16x
FORCE = AxSPEED2
c] IF DISTANCE INCREASES 9x THEN TIME INCREASES 3x
TIME = √DISTANCE
d] IF FORCE INCREASES 3x THEN ACCELERATION INCREASES 3x
ACCEL = AxFORCE
6 USE
INVERSELY AND DIRECTLY TO STATE EACH LAW VERBALLY:
Ex: ___ VARIES DIRECTLY WITH ___
a] VOLUME = k TEMPERATURE
VOLUME VARIES DIRECTLY WITH TEMPERATURE
b] VOLUME = k/PRESSURE
VOLUME VARIES INVERSELY WITH TEMPERATURE
c] VELOCITY = √MASS
VELOCITY VARIES DIRECTLY WITH SQUARE ROOT OF MASS
d] FORCE = k SPEED2
FORCE VARIES DIRECTLY WITH THE SPEED SQUARED
e] ACCELERATION = FORCE/MASS
ACCELERATION VARIES DIRECTLY WITH FORCE AND INVERSELY WITH MASS
f] FORCE = k MASS/DISTANCE2
FORCE VARIES DIRECTLY WITH MASS AND INVERSELY WITH DISTANCE SQUARED
7
DERIVE THE EQUATION FOR X:
a] Y = aX + b b] Y = a/X + b
Y – b = aX Y – b = a/X
(Y – b)/a = X X(Y – b) = a
X = a/(Y – b)
c] Y = a√X
d] Y = aX2 + b
Y2 = a2X
Y – b = aX2
Y2/a2
= X (Y – b)/a = X2
.
(Y/a)2 =
X √[(Y
– b)/a] = X |