Systematic Investigation
Types of Variables
Results
Juanita's Flight
Practice Questions
100
What is systematic investigation?
An investigation in which all variables are identified and recorded so that the investigation can be repeated.
100
What is an independent variable?
The variable that changes in an experiment.
100
What is a conclusion?
A decision based on an investigation and evidence.
100
Juanita has built a balsa wood glider with a 1m wingspan. Name two things she must do to know the distances of the shortest and longest flight.
1. She must measure the distance of each flight 2. She must record each distance she measures.
100
Jack hypothesized that robins prefer large birdhouses to smaller ones. He built four bird houses of different sizes to test his hypothesis. What was the independent variable in Jack's study?
The size of the bird house.
200
What is a research question?
A question used to focus on the purpose of the scientific investigation and the procedures used to complete it.
200
What is a dependent variable?
The variable that may or may not change.
200
What does reproducible mean?
Having the ability to get similar results from multiple trials.
200
Juanita considers shortening the wings, adding weight near the nose, and lengthening the tale (at the same time) of her glider. Why is this not the best method?Which variable would you test and why?
She should only test one variable at a time. She should add weight to the nose, because she can take the weight off if it does not work.
200
How does the scientific community conclude that a scientist's work is valid?
Other scientists carry out the same experiment to see if they get the same results.
300
What is a hypothesis?
An idea that can be tested by a scientific investigation.
300
What is a variable?
A changeable factor.
300
What is accuracy?
The degree of conformity of a measure to a standard or true value.
300
When flying her glider, how can Juanita keep wind speed and direction constant?
She should conduct er experiment inside, in a place like a gym.
300
In 1999, a team of researchers claimed that they made a new element. Two other teams repeated the experiment, but could not get the same results. The original team took back its claim. what do these events say about the process of scientific inquiry?
Experimental results must be reproducible to be accepted as valid.
400
What is a control group?
A set of observations in which no variables are changed.
400
What is a controlled variable?
Factors that should be kept the same.
400
What is a fair test?
An experiment in which one independent variable is tested by keeping all other independent variables the same.
400
Juanita is testing her glider's flight and is modifying to create the best version of it. She will add a 25 gram clip to the glider and throw it five times. Then she will move the clip to a different spot and throw it five times. What is the independent and dependent variable?
Dependent- how far the glider flies Independent- the 25 gram clip
400
Louis wanted to know whether a new brand of shoe could make a basketball player jump higher. He found 18 basketball players who started using the shoes this season and measured how high each player could jump with the new shoes. What error did he make in his investigation?
There was no control group for his study.
500
What is a sample size?
The number of observations made when gathering the data.
500
What is a constant?
Controlled variable that can be kept the same.
500
What is the best method for recording data?
A table
500
Juanita's friend, Charelle, says that Juanita should only throw the glider once after removing the clip. Why will this method produce a sufficient sample size?
Move trials are necessary for Juanita to determine the best place to add weight to the glider.
500
Annessa designed an experiment to study how temperature affects the rate at which an enzyme digests protein. She put equal amounts of liver into four equal-sized test tubes, brought the test tubes to different temperature, introduced equal amounts of enzymes to each tube, and measured the duration of the chemical reaction. What parameters were held constant in her experiment?
Liver mass, test-tube size, and enzyme amount
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