Pre-Class Tuesday 8-20-13

What do you need to make an accurate measurement?

(Hint: there is more than one possible answer)

SCIENTIFIC METHODSCIENTIFIC METHOD• State the problem• Gather information• Make a model (possible solution)• Form a hypothesis (guess what will happen)• Test the hypothesis by experiment• Analyze the data• Does it work? Modify the hypothesis and

repeat.

Making a Making a measurementmeasurement• Units:

describes the relative size or nature of a measurement (always follows a number)

• Standard: something everyone can agree

Solving A Measurement Solving A Measurement ProblemProblem

• Get into groups of two• Have one person

obtain two paper clips of different sizes

• Follow the instructions on the lab sheet

• Answer the questions at the end

The scientific standard for The scientific standard for measurement (p16)measurement (p16)

Prefixes are used to change SI units by powers of 10 (p16).

The base SI unit for length is the _____.

Wednesday Pre-Class 8-21-Wednesday Pre-Class 8-21-1313

A.Foot

B. Inch

C.Meter

D.Kilogram

Converting UnitsConverting Units• Units are not always supplied to us in a manner

that we need, so we convert them.• This changes the relative size of the unit, but not

the unit itself.– For example, a centimeter and millimeter both measure

length, just like a meter, but 1 centimeter is bigger than 1 millimeter (both are smaller than a meter)

• To convert smaller units to larger units, move the decimal to the left or divide

• To convert larger units to smaller units, move the decimal to the right or multiply

For a visual of this, go to the next slide

k (kilo)

H (Hecto)

D (Deka)

meter, liter, gram

d (deci)

c (centi)

m (milli)

Pre-Class 8-22-13 Thursday

Using the ladder method to convert units, find the answers to the following

problems:50 cL = ___ L (L is Liters)

0.3 kg = ___ g (g is grams)7500 dm = ___ Hm (m is meters)

Line Graph (p21)

Bar Graph (p21)

Pie Graph (p22)

Graphing Exercise

• Pie Graph (Exhaled Air)– Nitrogen 78%– Oxygen 16%– Carbon Monoxide 4%– Other 2%

• Bar Graph (Type of shoes)– Write types of shoes on

board– Count each type

• Line Graph (Driving Accidents per Time of Day)Midnight 13.13am 8.16am 9.79am 9.7Noon 13.13pm 16.06pm 15.49pm 14.1

Scientific Notation• Used to write really big or really small

numbers• The power of 10 counts the number of

zeros (for big) or decimal places (for small)• Big: 1000=103 100000=105

• Small: 0.001=10-3 0.00001=10-5

3 x 108 m/s

Pre-Class 8-22-13 Thursday

When using the ladder method to convert units,

you can move the _____ or multiply/divide by _____.