Western Sierra 2010-2011 UNIT 1 GENERAL SCIENCE TEST NAME______________PRD____DATE_______
Scientific Method and Experimental Design
Matching. Choices can be used more than once or not at all.
1)Independent Variable
2) Baseline
3) Controlled Variables
4) Placebo
5) Dependent Variable a) The effect being measured. b) Kept the same throughout to ensure clear, cause-and-effect, high quality results. c) All subjects are measured under normal conditions before being assigned to trials. d) The cause, which can be changed however the scientist wants. e) None of the above
While preparing to cook some pasta, Shaft noticed that the directions on the package said to add a tablespoon of salt to the water before boiling the pasta. He wondered what effect the salt would have on the temperature at which the water boils. Shaft thought that adding salt to the water would probably cause it to boil at a higher temperature. He decided to perform an experiment to see if he was correct. Shaft used a thermometer to determine the temperature of the water in each pot. He then added 2 grams of salt to one of the pots (B) and 4 grams of salt to another pot (C). Pots B and C both stopped boiling briefly. When they came back to a boil he took the temperature of each pot again. Shaft's data are recorded in the table below.
Pot
A
B
C
Temperature ( o C)
at first boil
100.3
100.3
100.3
Salt (grams)
0
2
4
Temperature ( o C)
at second boil
100.3
103.9
103.7
6) Based on his experiment, Shaft thinks that if he adds sugar to water then the results should change just like with salt. This idea is best referred to as: d) Experimental Design e) Hypothesis a) Theory b) Dependent Variable c) Placebo
7) The best way for Shaft to verify that his results are precise is to: a) Submit the results to the science director. c) Average each column of data. e) Try the experiment using sugar, pepper, and baking soda each.
8) The “Temperature at First Boil” measurement could be best described as a: a) Dependent variable b) Precision trial b) Repeat the experiment using the exact same procedure. d) Buy a fancier thermometer. c) Baseline d) Control Group e) Placebo

Western Sierra 2010-2011 UNIT 1 GENERAL SCIENCE TEST NAME______________PRD____DATE_______
Several students are entering a bridge building contest that requires using ice cream sticks and glue to construct the strongest bridge possible. The bridges must be 15cm wide and span a length of 30 cm.
9) Which of the following tests is the most accurate way to determine the strongest span design for these bridges? a) Roll toy cars across until it breaks. b) Place heavy construction blocks on the top center. c) Place light construction blocks on the top center. d) Stack coins on both ends of the bridge. e) Drop light construction blocks on it from ceiling height.
Ghengis Khan conducted an experiment that compared the effects of different sounds on the growth of bean plants. He planted bean seeds of the same type and size in nine containers using the same type of soil in each container. He placed the containers in the locations shown.
Container Location and Sound
1, 2, and 3 Bedroom with 4 hours of pop music per day
4, 5, and 6 Living room with 4 hours of television news per day
7, 8, and 9 Empty room with no sound
Ghengis Khan gave each plant the same amount of water at the same time each day. After two weeks, Ghengis observed that the plant in the living room was the largest and had the most leaves. Ghengis concluded that bean plants grow the fastest when exposed to television sounds.
10) Which is the greatest error that Ghengis made in his experimental design? a) Ghengis did not control other variables that might affect plant growth. b) Ghengis did not establish a baseline. c) Ghengis did not use a placebo. d) Ghengis did not conduct multiple trials. e) No errors were made.
11) Which of the following is the independent variable in this investigation? a) Sunlight b) Fertilizer c) Soil d) Water e) None of the above

Western Sierra 2010-2011 UNIT 1 GENERAL SCIENCE TEST NAME______________PRD____DATE_______
In Arkansas, scientists randomly assigned 4,416 people into two groups. They measured weight and mood for a period of 1 month.
They then gave Gogurt to 2,135 people, randomly chosen regular yogurts to 1,280, and no breakfast to 1,001. After three more months, they again checked on weight and mood.
12) What further questions might the scientists need to investigate before publishing their data? a) Were the eating habits of the three groups similar before the experiment? b) Were unique individuals offsetting? c) Did the packaging change the way subjects perceived the trials? d) Which brands of regular yogurts were included in the comparison group? e) The recommendation can be justified without additional information.
Scatterplotting and Analysis
13) Which graph(s) shows no correlation between mass and volume:
I) II) III) IV) a) I b) II c) II and IV d) III and IV e) I and II
14) A person repeatedly measures the time it takes a car to complete a lap of the Indy 500. She records: 18 s, 18 s, 16 s, 19 s, 18 s, 19 s. The margin of error or precision of this data is: a) 10% b) 18 s c) ± 1 s d) ± 2 s e) None of the above
15) Accuracy is: a) Affected by your procedure and equipment. c) Improved by averaging data of the same type across trials. e) None of the above. b) How close you are to the ‘right’ answer. d) All of the above.

Western Sierra 2010-2011 UNIT 1 GENERAL SCIENCE TEST NAME______________PRD____DATE_______
16) Design an experiment around the question: “Does the game of chess make you smarter?”
Brainstorm the different ideas you need to perform this experiment well (10 pts), and write these ideas into a step-by-step procedure (5 pts).
17) Analyze the data thoroughly:
Attempted
Speed
(mph)
15
20
25
30
Time
(min)
Trial 1
121
93
3.01
4.46
Time
(min)
Trial 2
119
92
2.98
4.48
Time
(min)
Trial 3
117
90
3.04
5.59
Dimensional Analysis (10 TH GRADE ONLY)
Show complete work to receive credit.
Include a:
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

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Scatterplot (4 pts), Fit (1 pt), Error Bars (1 pt)
Average (1 pt)
Precision (2 pts)
Correlation Type (1 pt)
Std. Deviation (10 th grade only) (1 pt)
18) Mr. Wurden’s purple mug holds 18 oz, whereas a traditional cup is 8 oz. Each pot of coffee is supposed to make 5 traditional cups. He brews a pot of strong decaf, which has .2 servings of caffeine per cup. If he drinks 3/5ths of the pot himself per day (and gives the other 2/5ths to Mrs. Dixon or Mr. Glasser) then how many ‘servings’ per day of caffeine does he drink? (3 pts)
What is the ratio of coffee pot to purple mug capacity? (3 pts)
If Mr. Wurden is instead being healthy and drinking only tea which has .75 servings of caffeine per cup, and drinks a quart of this tea per day in order to stay hydrated for cross country, how does his daily tea-based caffeine consumption compare to his daily coffeebased caffeine consumption? Use your planner if you need an oz. to qt. conversion. (4 pts)