Name _______________ Date __________ Block __
1.1.1 State and compare quantities to the nearest order of magnitude.
1.1.2 State the ranges of magnitude of distances, masses and times that occur in the universe, from smallest to greatest.

What is an order of magnitude?

Check this video out. http://www.youtube.com/watch?v=0fKBhvDjuy0

Scale Video

Three Volunteers
 Place the basketball and foam ball the correct distance apart.
 http://www.youtube.com/watch?v=Bz9D6xba9Og&list=PL772556F1EFC4D01C&index=1&feature=plpp_ video
Why does that matter?

Must have a consistent set of units agreed upon. (SI system)

SI has _______ fundamental units w/ lots of combinations.
 How far off were you?

Need an appreciation for the magnitude of things. (masses, time, distances, forces…)
1.1.2 State the ranges of magnitude of distances, masses and times that occur in the universe, from smallest to greatest.
Can you tell me the correct order of magnitude? (+18, -15, -23, +25, +50, -30)

Diameter of atomic nucleus = 10
???

Extent of visible universe = 10 ???

Electron mass = 10
???

Mass of Universe = 10
???
 Time of light passage across a nucleus = 10 ???

Estimated age of universe = 10
??
Distances

Sub-_________ particles = 10
-15 m

Extent of the visible universe = 10
25 m

Distance from Earth to Moon = 3.84 x 10
5 km

__________ of Earth = 6380km = 10 7 m

Diameter of a nucleus = 10
-15 m
Times

Passage of light across a nucleus = 10

Age of the ___________ = 10
18 s
-23 s

__________ to travel from Sun to Earth = 8min = 10
2 s

Period for one orbit of Earth = 365day = 10 7 s

Time between vibrations of Cesium = 10
-10 s
Masses

Rest mass of an ____________ = 10

The universe = 10
50 kg
-30 kg

Mass of the __________ = 5.97 x 10
24 kg

Mass of the Moon = 7.35 x 10 22 kg

Mass of an electron = 9.11 x 10
31 kg
1.1.3 Stating ratios of quantities as differences of orders of magnitude

10
-10 m/ 10
-15
m= 10
5

10
5 is known as a difference of five orders of magnitude.
 The ratio of the diameter of the hydrogen atom to its nucleus is about 100000 times or 10 5 times, or a difference of 5 orders of magnitude.

***NOTE***I want to first round the decimal to a 1 or 10

Example

The rest mass of a proton is about 1.67x10
-27 kg. The rest mass of an electron is about 9.1x10
31 kg. How many orders of magnitude bigger is the mass of the proton than that of the electron?

Example Solution - I want to first round the decimal to a 1 or 10
 ______________kg and _____________kg (1x10 -30 kg)

-27- -30 = 3 orders of magnitude

*** NOTE*** Realize that the proton is not 3 times more massive it is 10
3
times more massive or 1000 times more massive.
Practice 2

The length of a football pitch is about 100m. The distance from the earth to the moon is about 384x10
6 m.
How many orders of magnitude larger is the distance from earth to the moon than the length of a football pitch?

Practice 2 solution
 Football pitch =

Earth to moon =
Practice 3

The mass of the Sun is 1.99 x 10
30 kg. The mass of the Earth is 5.98x10
24 kg. How many orders of magnitude more massive is the Sun than the Earth?
Practice 3 Solution

Sun =

Earth =

Practice 3.1

A 2500kg T-rex is how many orders of magnitude larger than an 85g squirrel?

1.1.3 Stating ratios of quantities as differences of orders of magnitude
Practice 3.1 Solution
1.1.4 Estimate approximate values of everyday quantities to one or two significant figures and/or to the nearest order of magnitude. a.
Number of people in an NBA arena= _____ b.
Mass of elephant= _______ kg c.
Diameter of earth= _______ m d.
Speed of a commercial jet= ______ m/s e.
How high is a two story house in meters? f.
What is the diameter of your pupil? g.
How many times does your heart beat in an hour when you are relaxed? h.
What is the weight of an apple in Newtons?
Practice 7

Estimate the thickness of a page in your book.
Practice 7 Solution