1. Unit 2: Measurement and Motion

2. 2.1 Distance and Length
2.2 Time
2.3 Mass, Matter and the Atom

3. Chapter 2 Objectives Express lengths in metric and English units.
Convert distances between different units.
Calculate the surface area and volume of simple shapes.
Describe time intervals in hours, minutes, and seconds.
Convert time in mixed units to time in seconds.
Describe two effects you feel every day that are created by mass.
Describe the mass of objects in grams and kilograms.
Use scientific notation to represent large and small numbers.

4. *Students read Section 2.1 AFTER Investigation 2.1
2.1 Distance and Length
Key Question:
How do we accurately communicate length and distance?
*Students read Section 2.1 AFTER Investigation 2.1

5. Chapter 2 Vocabulary Terms
meter
centimeter
millimeter
kilometer
inch
foot mile
surface area
volume
weight
metric system
conversion factor
time
interval
precision
accuracy
kilogram
gram
mass
English system
atom
inertia
molecule
mixture
element
base
power of ten
exponent
scientific notation
distance
length

6. 2.1 Distance and Length measurement - a quantity and a unit distance -
is a length
the amount of space between two points

7. 2.1 Two Systems of Units Science problem solving requires both:
Metric system
English system

8. 2.1 Units of Length
The common units of measurement in the English system are inches, feet, yards, and miles.
These four length units are related to the meter.

9. 2.1 Convert Units conversion factor -
is the number by which you multiply or divide a quantity in one unit to express the quantity in a different unit.

10. 2.1 Convert length A football field is 100 yards long.
What is this distance expressed in meters?
1) You are given distance in yards.
2) You are asked to find distance in meters.
3) 1 yard = 3 feet, 1 foot = meters
4) Solve:
100 yards = 3 feet/1 yard x m/1 foot = 91.4 m

11. 2.1 Surface Area vs. Volume surface area -
is the measurement of the extent of an object’s surface or area without including its thickness.
volume -
is a measure of the space occupied by a object.

12. 2.1 Calculate surface area and volume
A basketball has a radius of 12.5 centimeters. Calculate the surface area and volume of the ball.
You are asked to find surface area and volume.
A ball is shaped like a sphere and you are given the radius.
Surface area: A = 4πr2; volume: V = (4/3)πr3
Solve...
1) You are asked to find surface area and volume.
2) A ball is shaped like a sphere and you are given the radius.
3) Surface area: A = 4 π r2; volume: V = (4/3) π r3
4) Solve:
A= 4 (3.14)(12.5)2 = 1,963 cm2
V = (4/3)(3.14)(12.5)3 = 8,181 cm3

13. *Students read Section 2.2 AFTER Investigation 2.2
2.2 Time
Key Question:
How do we measure and describe time?
*Students read Section 2.2 AFTER Investigation 2.2

14. 2.2 Time Two ways to think about time: What time is it?
3 P.M. Eastern Time on April 21, 2004,
How much time has passed?
3 hr: 44 min: 25 sec.
A quantity of time is often called a time interval.

15. 2.2 Converting Mixed Units
You are asked for time in seconds.
You are given a time interval in mixed units.
1 hour = 3,600 sec minute = 60 sec
Do the conversion:
1 hour = 3,600 sec
26 minutes = 26 × 60 = 1,560 sec
Add all the seconds:
t = 3, , = 5, sec

16. 2.2 Time Units

17. 2.2 Accuracy and Precision
is the quality of being exact and free from error.
how close a measurement is to the true value.
precision
is the degree of mutual agreement among a series of individual measurements, values, or results.

18. 2.3 Mass, Matter and the Atom
Key Question:
How is mass described?
*Students read Section 2.2 AFTER Investigation 2.3

19. 2.3 Mass, Matter and the Atom
is the amount of “stuff” an object contains.
Two effects mass has on matter:
weight
is the force of the Earth’s gravity pulling down.
Gravity acts on an object’s mass.
inertia
is the tendency of an object to resist changes in motion.
Inertia comes from mass.

20. 2.3 Measuring Mass kilogram -
is the mass of 1 liter of water or 1,000 cubic centimeters of water.

21. 2.3 Scientific Notation
Scientific notation works by expressing very small or very large numbers as the product of two numbers that are individually much easier to deal with.
The first number is called the base.
The second number is a power of ten.
The base is usually written with only one digit in front of the decimal point.
ex. 2,500 would be written 2.5 × 103
The small numeral 3 in 103 is called the exponent.

22. 2.3 Mass, Matter and the Atom
the smallest particle of an element that can exist alone or in combination with other atoms.
element
composed of all of the same kind of atom.

23. 2.3 Mass, Matter and the Atom
molecule -
is a neutral group of atoms that are chemically bonded together; it is the smallest particle of a compound that can exist by itself and retain the properties of the compound.
mixture -
is a substance that contains a combination of different compounds and/or elements and be separated by physical means.

24. 2.3 Mass, Matter and the Atom
The three most common forms of matter are called solid, liquid, and gas.
At temperatures greater than 11,000 °C the atoms in a gas start to break apart and form plasma.

26. 2.3 Mass, Matter and the Atom
Solids - Atoms in a solid stay together because the energy per atom is too low to break the bonds between atoms.
Liquids- Liquids flow because atoms have enough energy to move around by temporarily breaking and reforming bonds with neighboring atoms.
Gases- Gas atoms have enough energy to completely break bonds with each other.
Plasma- In plasma, matter becomes ionized as electrons are broken loose from atoms.

27. Application: Nanotechnology
miniature cell pump
micro T.V. mirrors
smaller
than insect legs