The Scientific Method Mr. Luis A. Velazquez

What is the scientific method? Is a step by step process to understand nature. Scientists use an experiment to search for cause and effect relationships in nature. In other words, they design an experiment so that changes to one item cause something else to vary in a predictable way.

What are the steps in the scientific method? Define the problem Gather information Make an hypothesis Test your hypothesis Review your results Make a conclusion

In an experiment these changing quantities are called variables, and an experiment usually has three kinds: independent dependent control What are variables?

The control variable Controlled variables are quantities that a scientist wants to remain constant, and he must observe them as carefully as the dependent variables. Why? Most experiments have more than one controlled variable. Some people refer to controlled variables as "constant variables."

The Independent Variable The independent variable is the one that is changed by the scientist. In an experiment there is only one independent variable.

The dependent variable The dependent variable changes in response to the change the scientist makes to the independent variable. The number of dependent variables in an experiment varies, but there is often more than one.

How to identify the dependent variable? To be predicted The response variable The outcome A variable that is not under the experimenter's control.

The cause The input The manipulated variable The variable that is changed on purpose in an experiment. How to identify the independent variable?

Difference between Variables Dependent –One or more –Output –Response variable –Results and data –Not controlled –Effects Independent –Only one –Input –Manipulated variable –Is under the control of the scientist –Cause

The SI Unit System Mr. Luis A. Velazquez

PREFIXSYMBOLFACTOR yottaY10 24 zettaZ10 21 exaE10 18 petaP10 15 teraT10 12 gigaG10 9 megaM10 6

PREFIXSYMBOLFACTOR kiloK10 3 hectoH10 2 dekaD10 1 decid10 -1 centic10 -2 millim10 -3 micro10 -6 nanon10 -9 picop femtof attoa zeptoz yoctoy10 -24

Prefix Kilo 10x 10 x 10 = 1000 = 10 3 Hecto 10 x 10 = 100 = 10 2 Decka 10x1 = 10 = 10 1 deci 1/10 = 0.1 = centi 1/100 = 0.01 = milli 1/1000 = = x1 = 1 = 10 0

How to remember? King Henry Died Drinking Chocolate Milk Basic unit K H D d c m mass, length, volume

Kilo Hecto Decka deci centi milli Basic Unit Grams, Liters, meter Left Right

Practice Problems Kilograms are bigger than Grams So you need to multiply this means you move the decimal to the right How many times? 3 5 Kg =_______ g Answer5000

Practice Problems centigrams are smaller than grams So you need to divide this means you move the decimal to the left How many times? cg =_______ g Answer.00045

Practice Problems Dekagrams are bigger than grams So you need to multiply this means you move the decimal to the right How many times? 1 36 Dg =_______ g Answer360

Practice Problems milligrams are smaller than Kilograms So you need to divide this means you move the decimal to the left How many times? 6 7 mg =____________ Kg Answer

Practice Problems Liters are bigger than milliliters So you need to multiply this means you move the decimal to the right. How many times? 3 9 L =_______ mL Answer9000

Answer tofollowing Problems 35L =.035 KL 46 g =.46 Hg mg = Dg 9.53 mm = m cL = L Hm = 5210 cm

35L =.035 KL Liter are smaller than Kiloliters so you divide or move your decimal to the left. You move your decimal to the left three times The answer is.035 KL

46 g = 0.46 Hg Grams are smaller than Hectograms so you divide or move your decimal to the left. You move your decimal to the left two times. The answer is 0.46Hg or.46 Hg

mg = Dg milligrams are smaller than Decagrams so you divide or move you decimal to the left. You move your decimal to the left four times. The answer is Dg

9.53 mm =.00953m millimeters are smaller than meter so you divide or move you decimal to the left. You move your decimal to the left three times The answer is meters

7.908 cL =.07908L centiliters are smaller than Liters so you divide or move you decimal to the left. You move your decimal to the left two times. The answer is Liters

0.521 Hm = 5210 cm Hectometer are bigger than centimeters so you multiply or move you decimal to the right. You move your decimal to the right four times. The answer is 5210 cm