Scientific Method & Hypotheses
When following the scientific method, what should a scientist do after forming a hypothesis?
Conduct an experiment (test the hypothesis)
Define "independent variable"
The factor that we change in an experiment
Which type of data uses numbers?
Quantitative
Define accuracy
How close to the true value our data is
What SI unit is used to measure mass?
Define hypothesis
A testable prediction
Define "dependent variable"
The variable we measure in an experiment
A student writes: "The water was cloudy." Is this qualitative or quantitative data?
Qualitative
Define precision
How close repeated measurements are to each other
What SI unit is used to measure volume?
Liter
True or False? The following sentence is an example of a valid hypothesis:
"If I water plants daily, then they will grow taller than plants watered weekly"
True
In an experiment testing how fertilizer type affects plant growth, what would be the independent variable?
Fertilizer type
Which type of graph is best for showing changes over time?
Line graph
A student measures 5.0 cm, 5.1 cm, and 5.0 cm. The actual value is 8.0 cm. Are the student measurements accurate, precise, both, or neither?
Precise only
Why do scientists use SI units instead of other measurement systems?
So scientists worldwide can compare data using the same system
Why do scientists write detailed procedures when running experiments?
So experiments can be repeated
Why is it important to keep control variables the same?
So you know that it's the independent variable that's causing the change
Bar graph
A student measures 4.0s, 4.1s, and 4.0s. The actual value is 6.0s. Are these results accurate, precise, both, or neither?
Precise
The Kelvin is the SI unit for ________.
Temperature
Why do scientists run multiple trials of an experiment?
To make results more accurate and reliable
A student tests whether energy drinks improve running speed. Identify the IV, DV, and two CVs.
IV: Type of drink
DV: Running speed
CVs: Same track, same time of day, same distance, same amount of drink consumed
What is the main reason a scientist might prefer to use a graph instead of a data table?
Graphs can make it easier to identify patterns/trends in data
A class collects these times for a pendulum swing: 3.1 s, 3.0 s, and 3.2 s. Actual time was 3.0 s. Are the results accurate, precise, both, or neither? Why?
Both. The measurements are both close to the actual time (all within 0.2s of the actual) and close to one another (all within 0.2s of each other).
True or False: A kilogram is equal to 1000 grams
True