Concepts Of Science. Chapter 2

Front 1

Occam's razor (the Rule of Simplicity)

Back 1

when confronted w/ phenomena in the physical world, we should accept the most straightforward, reasonable explanation as the most likely. simplest solution to a problem is most likely to be right

Front 2

William of Occam

Back 2

"postulates must not be multiplied w/out necessity"

"it is vain to do w/ more what can be done w/ fewer"

Front 3

astronomy

Back 3

1 of the first sciences to develop because night sky has been an integral part of sensory experience since our awareness of nature. curiosity of changing patterns of stars as night passes & year progresses

Front 4

basic tenet of science

Back 4

physical events are predictable & quantifiable

Front 5

archaeoastronomy

Back 5

study of astronomy in archaeology & human history

Front 6

stongehenge

Back 6

observatory that also functioned as a giant calendar, built in stages starting about 2800 yr BC; useful for measuring time & seasons required of an agricultural society; still functions after more than 4000 yrs

Front 7

babylonians & other ancient societies

Back 7

developed myths & stories to explain motion of stars & planets, which wasn't science

Front 8

greeks

Back 8

made up myths & stories, but also made observations & predictions; believed in perfection of the heavens

Front 9

Ptolemy (200 AD)

Back 9

Greek astronomer. proposed 1st comprehensive explanation of motions of the stars & planets based on observations

Front 10

Ptolemaic theory

Back 10

Earth is center of universe & stars revolve around Earth on a series of concentric spheres, while the planets are part of smaller spheres rolling around within the larger spheres w/ the stars. adequate to explain observations for over 1500 yrs

Front 11

copernicus

Back 11

proposed that the sun is the center of the universe & that stars & planets occupy spheres moving around the sun

Front 12

Tycho (1546-1601)

Back 12

helped to understand how the solar system works; his great mass of data allowed Kepler to develop new laws about solar system motions

Front 13

Kepler (1571-1630)

Back 13

helped to understand how the solar system works; Tycho's great mass of data allowed him to develop new laws about solar system motions (mechanics of solar system); discovered that planet motion is an ellipse (not a circle) w/ the sun @ one focus of the ellipse

Front 14

Galileo (1564-1642)

Back 14

founder of modern experimental science & astronomer. challenged the prevailing view of perfection in the heavens using a new device (telescope) to directly observe astronomical objects (ex: showed that 4 moons revolve around Jupiter) tried by Catholic Church for heresy b/c of his confrontational nature)

Front 15

Newton (1642-1727)

Back 15

synthesized work of Galileo, Kepler, & others into statements of basic principles of motion about everything in the universe; Laws of Motion

Front 16

mechanics

Back 16

outgrowth of Gallileo's experimental work with objects in motion

Front 17

speed

Back 17

distance an object travels/time of travel (s=d/t)

Front 18

velocity

Back 18

speed with information about direction. proportional to the length of time that it's been falling. v=g(m/sec^2)*time(sec)

Front 19

acceleration

Back 19

amount of change in velocity/time it takes for change to occur (a=(Vf-Vi)/t)
whenever an object changes speed or direction, it accelerates

Front 20

galileo's dropping experiments

Back 20

showed that all objects falling have constant acceleration
(g=constant acceleration of gravity=9.8m/sec^2=32ft/sec^2)

Front 21

first 3 seconds of a fall

Back 21

1) 9.8 m/sec
2) 19.6 m/sec
3) 29.4 m/sec

Front 22

newton's first law of motion

Back 22

a moving object will continue moving in a straight line @ a constant speed, & a stationary object will remain @ rest (iow: pushing or pulling is required to move an object)

Front 23

Newton's 2 kinds of motion

Back 23

uniform motion & acceleration

Front 24

uniform motion

Back 24

travels in a straight line @ a constant speed

Front 25

*acceleration

Back 25

motions involving changes in speed, direction, or both

Front 26

concept of Force

Back 26

something that produces a change in the state of motion of an object

Front 27

concept of Inertia

Back 27

tendency for an object to remain in uniform motion

Front 28

Newton's second law of motion

Back 28

the acceleration produced on a body by a force is proportional to the magnitude of the force & inversely proportional to the mass of the object (tells us what the force (f) does when it acts) f=m x a. defines the balance between force & motion in producing an acceleration

Front 29

mass

Back 29

amount of matter in an object

Front 30

force

Back 30

something that causes a mass to accelerate. always act simultaneously in pairs

Front 31

Unit of Force

Back 31

newton (N). 1 N=1 kg m/sec^2

Front 32

Newton's third law of motion

Back 32

for every action, there is an equal and opposite reaction (whenever a force is applied to an object, an equal force of opposite direction is exerted by the object

Front 33

gravity

Back 33

the universal force. no difference in gravity on earth and gravity in space

Front 34

newton's universal law of gravitation

Back 34

between any 2 objects in the universe, there is an attractive force (gravity) that is proportional to the masses of the objects & inversely proportional to the square of the distance between them

Front 35

weight

Back 35

force of gravity on an object located @ a specific point