cahier physique - physics workbook

Introduction

watch movie about powers of ten. Why do we need the powers of ten in Physics?
http://www.youtube.com/watch?v=o69c2hdvojY

Scientific notation

1) Reading: Measurements that are very large or very small values are usually expressed in scientific notation. Scientific notation consists of a number equal to or greater than 1 and less than 10 followed by a multiplication sign and the base ten raised to some integral power.
example: 3x 10⁴ (or 3E4 on your TI or 30,000 in standard notation)
3 x 10^-4 (or 3 E-4 on your TI or 0.0003 in standard form),
23 x 10³ is not a scientific notation because __________________
The mean radius of the Earth is 6,370,000. m in standard notation but 6.3 10⁶m in scientific notation. On the TI type : 6.3E6
From the decimal point you jump 6 times to reach a number smaller than 10 backward so the exponent is 6 and it is positive (big number, larger than 1 = positive exponent)

The universal gravitation constant is G = 0.000 000 000 066 7 Nm²/kg² =
6.67 10^{- 11} Nm²/kg^2. On the TI type 6.67 E-11/
From the decimal point, jump 11 times. The exponent is 11 and negative. (number smaller than 0). Keep these examples in mind.

watch this video:
on discovery streaming movie about scientific notation
http://player.discoveryeducation.com/index.cfm?guidAssetId=96D7582F-2FAA-4D63-8003-9269F1DD8AA2
see 4:40mn

2) Write in scientific notation:
A) 68,000,000 working women in the US _____________________
B) 78,000,000 working men in the US ___________________
C) Using google find out the population of the U.S. now ________
and convert to scientific notation_________
____________
D) using google find the distance Sun - EArth:
standard notation _______________ scientific notation _____________
E) 0.000005 g is the mass of an amoeba ________
what is an amoeba ____________
F) 0.000000002 g is the mass of a one liver cell _____________
G) 0.00024 is the probability of four of a kind in poker ________________
H) 0.0035 in the number of onces in a gram _____________
I) 0.00000009 is the wavelength of an X.ray in centimeter _______
J) count the number of students in the center right now ____________
in scientific notation __________
K) population of France now ______________ in standard notation
and in scientific notation __________________

2) Write in standard notation:
A)2.35 10² pounds of meat consumed per person per year in the United states.
B) 8 x 10⁶ bagels eaten per day in the United States
C) 4x10^-2inches in 1mm ________________
D) 4 x 10^-11 joules of energy released by splitting one uranium atom
E) 1.68 10¹⁰ estimated worth of the wealthiest men
F) 2.3x10^-1 kilowatts per hour used by your TV
G) 10^-9 s the time for the light to travel 1 foot.
H) 10⁰ m the length of your arm (about) ________
I) 5 10⁰s for the sound to travel 1 mile

3) When you multiply numbers in scientific notation with like base, add the exponents.
When you divide, subtract the exponent.
3 10⁴ x2 10³ = 6 10⁷ ; 3 10⁴ / 2 10³ = 1.5 10¹ ; 310⁴ /2 10 ^-2 = 1.5 10⁶ ;3 10^-4 / 2 10^-5 = 1.5 10¹
Try now on your TI:
3E4 x 2 E3 = ________ 3E4/2E3 = _______3E4/2E-2 = ______ 3E-4/ 2E-5 = _____

4) The average American eats 160 pounds of vegetables each year. Since there are 290 million Americans, the number of pounds of vegetable each year should be:
_________ x ________ = __________ (in scientific notation, 1 million = 1,000,000)
write this number in standard notation ___________

5) The average American drinks 54.2 gallons of soft drinks each year. Since there are about 290 million Americans, the number of soft drinks consumed each year should be ___________ in scientific notation __________________in standard notation

6) Nuclear fission is used as an energy source. The amount of energy released by a mole of uranium 235 (mass = 235g) is 4.7 10⁹kilocalories. So the amount of energy a gram of uranium 235 releases is __________________ in scientific notation.

7) The velocity of light can be measured by dividing the distance from the sun to the earth (1.47 10¹¹ meters) by the time it takes for sunlight to reach the earth
(4.9 10² seconds). Thus the velocity of light is ____________ in scientific notation
and _________ in standard notation . 4.9 10² seconds is _______ minutes

8) Astronomers also measure distances in light years (the distance light travels in 1 year). 1 light year = 9.46 10¹²km. The closest star, Proxima Centauri, is, 4.22 light years away. In the scientific notation, rounded to 2 decimal places,
how many kilometers is that ?

9) Astronomical distances are so large that they are measured in astronomical units (A.U.) for short. An astronomical unit is defined as the average separation (distance) of the earth and the sun, that is, 150,000,000 kilometers (so 1 A.U. = 150,000,000km). WRite 1 A.U. in scientific notation. _____________
Using google find the distance Sun - Pluto in kilometers _________
. convert to A. U ______________ in scientific notation (keep 2 decimals)

10) Use 9). Distances in astronomy are also measured in parsecs. 1 parsec = 2.06 105 A.U. Thus
1 parsec = _________________ kilometers (use (9)

11) 1 parsec = 3.09 10¹³ km and 1 light year = 9.46 10¹²km, the number of light years in a parsec is ________________ in scientific notation.

International System (SI) and the Metric system

1) Fill the blanks. The units in which physical quantities are measured are shown below:

base quantity	base unit	symbol
length	meter	m
time	second	s
mass	kilogram	kg
temperature	kelvin	K

A wide variety of other units, are combinations of the base units:
speed s is measured in m/s
Since the unit for speed is m/s it means : to find a speed
you divide the _________ in meters by the ________ in seconds. or V = d/t
The speed V is the distance covered (m) in 1 second.
So if V = 30m/s, it means you cover ______ m in 1 second or ______m in 1 hour.

acceleration a is measured in m/s²or m/s/s
Since the unit for acceleration is m/s/s or (m/s)/s it means: to find an acceleration your divide the _________ (m/s) by a _______ (s). or a = ____ / ____ (use V and t)
The acceleration a is the increase (or decrease) of speed in 1 second. So if a = 9.8m/s/s, it means the speed is increases by _____ m/s every second.

force (unit of pull) is measured in newtons (N) or kg . m/s²Since the unit for a force is kg m/s² or kg x (m/s²) it means: to find a force you multiply a
_______ (kg) by an ___________ (m/s²). Or F = _____ x _____ (use m for mass and a)
^{So if a mass of 1 kg has an acceleration of 1 m/s/s (the speed increases by 1m/s every second)
it means that a force (pull) of ____ N is exerted on the mass. (use F = ma)
If a mass of 1kg has an acceleration of 10 m/s/s, the force is _____ N}Energy is measured in joules (J) or kg m²/s² or kg (m/s²) m
don't worry about energy, we will study it in 10th grade.

Momentum is measured in kg m/s
momentum will be studied in 10th grade.

Area is measured in m² and volume in m³
To find an area (m² = m x m) you multiply a ____ (m) by the ________ (m)
To find a volume (m³ = m xm xm ) you multuply a ______ by the _____ by the _____.

density is measured in kg/m³or g/cm³
Since the unit is kg/m³ , to find the density you divide a ________(kg) by
a _______ (m³). Or density = ____ / _____. (use m for mass and V for volume)
So the density is the mass of an object per unit volume (1m³).

Pressure is measured in N / m² (or newtons/ m²)
The unit tells you that to find the pressure you divide the ______ (N) by a ______ (m³).
or Pressure = ____/ _____ (use P for volume and V for volume).

2)The weight of an object is measured in newtons so weight is a ___________.
It is the ________ acted at a distance by the EArth on this object.
the mass of the object is measured in __________
REmember that: to find the weight of an object on EArth, multiply its mass in kilograms by 9.8. So if m= 5 kg, weight = _______ N
If m = 100 kg, weight = ________N
if m = 0.01 kg, weight =

3) read: You need to be comfortable with the metric system and know how to convert km to m, kg to g etc... Always remember the table:

Prefix	Mega-	Kilo-	Hecto-	Deka-	BASE UNIT- M eter Gram Liter ...	Deci-	Centi-	Milli-	Micro-
Means	10⁶	1000	100	10	1	1/10	1/100	1/1000	1/10⁶
Symbol*	^Mm	km	hm	dam	m	dm	cm	mm	^µm**
	Mg	Kg	hg	dah	g	dg	cg	mg	µg

Remember the prefixes with the following acronym:

Miss Kathy Has Dirty U nderwear; Don't C heck Mine, M ister
\
4) 5km = _____m ; 4.2 km = ____m ; 1877m = ____km ; 157 m = ____km
182cm = _____m ; 43cm = ____m ; 22m = ____cm ; 4.5 m = __________450cm
3m = ________mm ; 0.35m = _____mm ; 2358mm = ____m ; 425 mm = ____ cm
30cm = ______ mm ; 2.4cm = _____ mm ; 67mm = ____ 6.7 cm ; 184 mm = ______ cm

5) 5kg = ____g ; 5.6 kg = _______g ; 1932 g = ______kg ; 342 g = ______kg
4 g = _____mg ; 0.23 g = _______mg ; 3294 mg = ____g ; 493 mg = ______g
342g = ____kg ; 0.03 g = _______mg ; 0.43204 cg = ________ µg

6) Fill the table below. first write the distance (km) in scientific notation,
convert to meters (m) in scientific notation, convert the period in years to
seconds. ( hints: 1 year = 365 days, 1 day = 24 hours, 1 hour = 3600 seconds
so 1 year = 365 x 24x 3600 s)

Planet	average distance from sun in Km standard notation	distance in km scientific notation	distance in m scientific notation	orbital period in EArth years (time for the planet to go around the Sun)	orbital period in seconds scientific notation
Mercury	58 000 000	=	=	0.24	=
Vernus	108 000 000	=	=	0.62	=
Earth	150 000 000	=	=	1.00	=
Mars	229 000 000	=	=	1.88	=
Jupiter	777 000 000	=	=	11.9	=
Saturn	1 426 000 000	=	=	29.5	=

13) match the object with their size in meters:

atomic radius 10^-4 meters = 0.0001m
circumference of EArth 10^-7 meters = 0.0000001 m
distance of observable universe about 5 meters (in 10⁰ order)
diameter ot human hair 10⁷ (E7) meters = 10,000,000 m
diameter of a virus 10²⁷ (E27) meters
length of a whale 10^-12 (E-12) meters = 0.000000000001m

14) use wikipedia or google:
The mass of the EArth is about ____________ kg (scientific notation)
The mass of an electron is about ___________ kg (scientific notation)
Find the ratio : mass EArth / mass electron (divide both quantities) = ___________

CONVERSION

1) Read. Say a speed is 443 m/s and you want to convert to km/h
Follow the step : 443 m = 0.443 km
1 s = 0.000278 hours (1 hour is 3600 s so 1 s = 1/3600 s )
so 443 m/s =0.443 km /0.000278 hours = 1594 km/h (about)

your turn:
987 m/s = _______ km/h ; 391 m/s = _______ km/h ; 921 m/s = ______ km/h

3) let's say you want to convert 3245 km/h to m/s
3245 km = 3,245,000 m
1 hour = 3600s
so 3245km/h = 3,245 000 m / 3600 s = 901 m/s (about)

your turn:
4392 km/h = ________ m/s ; 6321 km/h = _______ m/s ; 6421 km/h = _____ m/s
7000 km/h = _______ m/s

We will see over examples as we go through our chapters. The idea is always the same.