Name: ______________________________ Pd: ________ Due Date: Friday, Feb. 7th
SCIENCE SKILLS HOMEWORK
PART I:
SCIENTIFIC METHOD
Terrance Bogg, a well known British billionaire, is found dead on the floor of his office at 7:00 pm Saturday evening. He has been shot through the chest. Inspector Green of Scotland Yard is called in to solve the mystery. He discovers the following facts:
1) Bogg was shot with a 9mm handgun. The handgun is not in the office now. 2) The butler heard the shot at 4:50 pm. He thought it was a car backfiring.
3) The crime scene investigators, who looked at the body around 7:45 pm, said that Bogg had been dead for three to four hours at that time.
4) Two people had recently threatened Bogg. AJ Stokes hated him because Bogg was ruining his business. Gladys Jones, who used to be Bogg’s secretary, was fired last Friday. She was seen down at the local tavern yelling that “Bogg should be shot!”
5) AJ Stokes says that he was at a family reunion from 2:00 pm to 5:00 pm Saturday afternoon.
6) Gladys Jones was in a car accident at 3:00 pm Saturday afternoon. She has been in the hospital ever since with a broken leg and arm.
7) AJ’s wife says that he left the family reunion around 4:30 pm to meet with his financial planner.
8) AJ’s financial planner said that AJ has not had an appointment with him in weeks, let alone last Saturday. From these facts, Inspector Green guesses that AJ killed Boggs. He gets a search warrant and searches AJ’s house. He finds a 9mm handgun hidden in AJ’s garage. In a police lab test, the gun fires a bullet exactly like the one found in Bogg’s chest. AJ is arrested for the murder. Another case is solved by the famous Inspector Green!
Detectives and Scientist have a lot in common. They both have to figure out mysteries. They go about solving these mysteries in the same way. First a detective or scientist will decide what problem they are going to solve. Next, he or she must make a careful guess, based on some known facts, about what is really happening. Then he or she must test the guess by doing an experiment. Finally, he or she formulates a conclusion and decides whether the guess was correct. This way of solving problems is called the scientific method.
In the above story, how does Inspector Green handle each step of the scientific method? Scientific Method Solving the mystery
What is the problem or question to solve? Research and find the facts
Form a hypothesis (an educated guess)
Test the hypothesis (experiment)
Accept or reject the hypothesis
Step 1: The Question
Scientists often decide on the problems or mysteries they want to solve. There are thousands of questions in our universe that are waiting to be answered. Detectives are usually assigned a question, just like students are assigned questions to answer.
It is important to read a question carefully before trying to answer it. Many people give wrong answers because they don’t take the time to figure out what the question is asking.
Suppose you were asked the question: What is the average yearly rainfall in Utah?
1) The answer to this question would be: a) a word
b) a number c) a place
d) somebody’s name
2) What unit of measurement will the answer most likely be in? a) cm
b) m c) km d) miles
Step 2: Research/ Find the Facts
A fact in science is something that can be proven by observation (seeing something with your own eyes) or measurement (using a tool like a ruler, a scale, or a stopwatch to find differences that you cannot see very easily). Often people confuse their opinions with facts. Opinions are statements that depend on a person’s values (the things the someone likes or considers important). Opinions cannot be proven and values cannot be use to prove facts.
One other common problem some students have is separating facts from inferences. An inference is a conclusion that you have arrived at (sometimes correctly, sometimes incorrectly) based upon some fact.
Identify the following as either a fact or inference:
_____ The highway patrolman has pulled over a man driving a red Ferrari. _____ The man in the red Ferrari was speeding.
_____ Joshua did not eat his beans at lunch. _____ Joshua does not like beans.
_____ Samantha likes cooking.
_____ Samantha cooked dinner for her family
Step 3: Form a Hypothesis
After scientists have collected all of the facts they can about the problem they want to solve, they can make a careful guess about the solution. This educated guess is called a hypothesis (plural hypotheses). It is usually written as an “If…, then…” statement. For example, “If Tommy is soaking wet when he comes inside, then it must be raining outside.” Most people make hypotheses every day. Each hypothesis should be the best guess that can be made at that time based on the available facts. A good hypothesis must fit all the facts available. A good scientist never ignores facts just because they don’t fit in to his first ideas. Instead, he/she changes his/her ideas to fit all the facts.
Try making a hypothesis for the following situations:
1) You are watching TV and the screen goes black. You try turning on the lights, but nothing happens.
3) Greg is an employee of yours. He asked for time off on opening day of deer hunting, but you could not let him off. On opening day of deer hunting Greg’s wife calls in and says Greg is too sick to come to work.
4) Just before Christmas, your parents spend a lot of time in the basement workshop. You are not allowed to come into the workshop without warning them.
5) Your department leader at work has taken a job with another company. You have a good chance to be promoted to her job. The boss calls you into his office, saying he has good news for you.
Step 4: Test your Hypothesis
Once a scientist has made a hypothesis, he should test it out. The most common way to check a hypothesis is to do an experiment. In an experiment, a scientist takes a group of people or things, called subjects. He puts them in a situation where everything is the same except the one thing he wants to test. He usually leaves one thing in its natural state, and this is called the control. The one thing he wants to test is called a variable. The independent variable is the variable whose values have been selected by the scientist to test their relationship to the observations. The dependent variable is the variable that changes as a result of the experiment. The scientist then records the results of the experiment and checks to see if the results match his hypothesis.
Properties of a good experiment:
1- The subjects need to be similar, and there should be more than one subject for each group. 2- All conditions of the experiment should be the same, except the one variable being tested. 3- There should be a control group.
4- The results should be reproducible.
If an experiment does not meet these requirements, the results are not valid (true, dependable, reliable). Being able to set up a good experiment with valid results is a good scientific skill.
The following example experiments do not meet the requirements. What is wrong with them?
1. A teacher wanted to find out if teaching for a short time worked better than teaching for longer periods of time. She cut all of her classes from 90 minutes to 45 minutes long. Most of her students passed at the end of the semester, so she decided that shorter classes were better.
3. A farmer wanted to know if ABC fertilizer would be good for his sugar beets. He fertilized all his beets with ABC, but didn’t put any fertilizer on his green bean plants. His beets didn’t do well at all, but he got a great crop of beans. He concluded that ABC fertilizer was a waste of money.
Step 5: Accept or Reject your Hypothesis
After a scientist has chosen a problem, collected facts, formed a hypothesis, and tested it out with an experiment, she is ready to decide if the original hypothesis is correct or incorrect. A scientist must be willing to admit that her hypothesis may have been wrong, if the evidence indicates that. She can try doing different tests or choosing a different hypothesis and starting the scientific method over again. If the hypothesis is correct, then she may form a theory. A scientific theory is an idea or explanation of how things work based upon facts, evidence, and experimentation. Scientists can never be totally sure about their theories because new evidence is always
contradicting old theories. Think of a theory as the best working explanation for how something works based on all of the evidence we have right now. A law is a theory that almost every one accepts as true. Laws explain how things work, but not necessarily why they work that way.
1. What is the difference between a hypothesis, a theory, and a law?
PART II:
VARIABLES
Slimotosis
Sponge Bob notices that his pal Gary is suffering from slimotosis, which occurs when the shell
develops a nasty slime and gives off a horrible odor. His friend Patrick tells him that rubbing seaweed
on the shell is the perfect cure, while Sandy says that drinking Dr. Kelp will be a better cure. Sponge
Bob decides to test this cure by rubbing Gary with seaweed for 1 week and having him drink Dr. Kelp.
After a week of treatment, the slime is gone and Gary’s shell smells better.
1. What was the initial observation?
2. What is the independent variable?
3. What is the dependent variable?
4. What should Sponge Bob’s conclusion be? What was flawed with the experiment?
Patrick believes that fish that eat food exposed to microwaves will become smarter and would be
able to swim through a maze faster. He decides to perform an experiment by placing fish food in a microwave for 20 seconds. He has the fish swim through a maze and records the time it
takes for each one to make it to the end. He feeds the special food to 10 fish and gives regular food
to 10 others. After 1 week, he has the fish swim through the maze again and records the times for each.
PART III:
Graphing
1. Describe when you would use the following type of graphs
2. You are trying to show the percentage of your weekly allowance that goes
towards buying food (you also buy movie tickets, clothes and shoes).
What type of graph would you use?
1. What was Patrick’s hypothesis?
2. What is the independent variable?
3. What is the dependent variable?
LINE GRAPH:
BAR / COLUMN GRAPH:
PIE CHART
3. You are trying to plot a plant’s growth against the amount of time it takes.
What graph would you use?
4. Below, graph the affect of age on Rebecca Black’s Youtube video views on
a scatterplot (connect the dots). Do not forget to label x and y axes as
well as the proper units on those axes.
PART IV:
The Metric System & Units
Fill in the following chart with name of the unit, prefix, and physical quantity:
Unit Name Prefix Physical Quantity
70 dm 1.) deci- 2.)
10 cL Centiliter 3.) 4.)
5 ms 5.) milli- 6.)
78 kL kiloliter 7.) 8.)
10 Hm 9.) 10.) Length
Which physical quantities do the following metric units describe:
11.) meter - __________________ 12.) second -______________________
13.) kilogram - ___________________ 14.) liter - ________________________
Rebecca Black’s “Friday” Youtube Views by Age Group in 2012
Age Group Views
0-9 5,000,000
Convert the following from one unit to another (30-37):
15.) 100 km = _________ m 16.) 1 ms = _______________ s
17.) 10 L = _________ kL 18.) 600 cg = _____________ mg
19.) 31415 dm = ______ Hm 20.) 3.14159 s = _________ ms
