### Scientific Method

```Is a way of gaining understanding
through a series of steps which include
asking and answering questions,
gathering information and conducting experiments,
and documenting findings.
Scientific Method
 http://www.youtube.com/watch?v=eA86dYxrg4Q
 Scientific Method
Ask a Question / State the Problem
 Through careful observations, questions arise. Thus, good
science investigations begin with a question.
 The question should be one that leads to an investigation that
will yield quantitative or qualitative data.
 A problem statement is a question that compares variables:
 What effect does the drop height of a tennis ball have on
the bounce height of a tennis ball?
Independent Variable – drop height
Dependent Variable – bounce height
Collect Information
 Investigate or do some research in order to make an
educated guess or hypothesis.
 Consult at least two or three sources which will be
listed in a bibliography.
 Draw connections between research and project in lab
report.
Gathered Information
 Energy is neither created nor destroyed, but transformed
from one form to another.
 “When you hold the ball in the air, it’s full of potential
energy. When you drop the ball, the potential energy is
converted to kinetic energy (energy of motion). As it
bounces back up, the kinetic energy is converted back to
potential energy. However, the ball will not return quite as
high as you dropped it since some of the energy is
transformed into heat and sound in the collision with the
floor.”
http://books.google.com/books?id=JszH_d5gqSkC&pg=PA67&lpg=PA67&dq=does+the+drop+height+affect+the+boun
ce+height+of+a+ball&source=bl&ots=lpvY1b_yyx&sig=4tDVvEhXyvXnofyIi-FRrLJ_qUs&hl=en&sa=X&ei=aNvUMbdDsm42QXphYDYCQ&ved=0CEkQ6AEwBA#v=onepage&q=does%20the%20drop%20height%20affect%20the%
20bounce%20height%20of%20a%20ball&f=false
Gathered Information
 “Elevating the ball to a certain height will cause it to
gain gravitational potential energy that is equal to the
amount given by the equation E = mass x gravity x
height (Thus, it can be noted that the higher the
height of the ball, the more potential energy it has). As
soon as the ball is released, that gravitational potential
energy is transformed into kinetic energy”
http://www.reference.com/motif/science/what-affects-the-bounce-height-of-a-ball
Gathered Information
 “If you drop the same ball on the same surface, the
height it bounces back to will be the exact same
relative to the height you drop the ball from. In other
words, if you drop the ball and it bounces back to half
the height from which you dropped it, when you drop
it again from the halfway height, it will bounce a
quarter of the way back. This is called the coefficient
of restitution. Inflation will affect the coefficient of
restitution.”
http://books.google.com/books?id=JszH_d5gqSkC&pg=PA67&lpg=PA67&dq=does+the+drop+height+affect+the+b
ounce+height+of+a+ball&source=bl&ots=lpvY1b_yyx&sig=4tDVvEhXyvXnofyIi-FRrLJ_qUs&hl=en&sa=X&ei=aNvUMbdDsm42QXphYDYCQ&ved=0CEkQ6AEwBA#v=onepage&q=does%20the%20drop%20height%20affect%20th
e%20bounce%20height%20of%20a%20ball&f=false
Form a Hypothesis
 A hypothesis is an educated guess / prediction based
on information gathered and includes an explanation.
 Written as a If…then… Statement, includes because
 The hypothesis statement will be proven valid or
invalid by the experiment.
If I increase the height from which a ball is dropped,
then the bounce height will increase
because there is greater potential energy which
turns to kinetic.
Experiment – Test the Hypothesis
 Is a planned way to test the hypothesis and find the
answer to the problem statement.
 Is a way to collect data and determine the value of the
dependent variable.
 Only tests one dependent variable at a time.
 Compares independent variable to the dependent
variable.
Experiment – Test the Hypothesis
 Constant – is what remains the same in the experiment
 Variable – is what changes in the experiment
 Independent Variable

changed by experimenter

known before the experiment
 Dependent Variable

result of the change, thus depends upon the Independent Variable

discovered during experiment
Observe and Record Data
 Record data in tables.
 Include Title:

Bounce Height of Dropped Tennis Ball.
 The first column lists the independent variable.

Dropped height of the tennis ball
 The first row of table lists the dependent variable.

Bounce height of tennis ball
 Within the grid, the data is collected.
Observe and Record Data
 Transfer Data from Table to a Graph:
 Line Graphs –



Compare Independent and Dependent Variables
Place Independent Variable on the x-axis
Place Dependent Variable on the y-axis
y-axis
x-axis
Analyze Data - Draw a Conclusion
 State the Facts!
 Give the averages for each independent variable
 Say Why!
 Summarize data.
 Explain observed trends /result.
 Was your hypothesis supported? Why or why not?
 Wrap it Up!
 Discuss questions you may still have
 Sources of error
 Future testing possibilities
Report Results
 Use Scientific Method Lab Write-Up:
I. Purpose
What can be learned from doing the experiment?
II. Hypothesis
III. Materials
A list of needed equipment and supplies
IV. Procedure
Exact step by step process followed to complete experiment
Identify precautions and safety measures
Identify variables: controlled, independent, dependent
V.
Observations
Qualitative and Quantitative / Tables and Graphs
VI. Conclusion
What was learned, reliability, areas of improvement
Table:
The effect of drop height on the bounce height of a tennis ball
Height
Dropped
25 cm
50 cm
75 cm
100 cm
150 cm
Height Ball Bounces
Trial 1
Trial 2
Trial 3
Average
Add T1, T2,
T3 Divide by 3
Table:
1st hour
The effect of drop height on the bounce height of a tennis ball
Height
Dropped
Height Ball Bounces
Group 1 (J)
Group 2 (F) Group 3 (A)
Group 4 (T)
25 cm
14 (13.33)
16 (15.33)
10 (14)
50 cm
30.67 (34.3)
30.33 (31.67) 34 (33.7)
32 (34)
75 cm
46 (44.7)
46.33 (39.33) 65.3 (46.7)
48 (50)
100 cm
63.3 (61.7)
62.67 (66)
58.3 (66)
62 (63.2)
150 cm
93.3 (93.7)
88 (91.33)
94.67 (89)
82 (90)
18.33 (16.8)
3rd hour
Table:
The effect of drop height on the bounce height of a tennis ball
Height
Dropped
Height Ball Bounces
G1T
G2 K G3 Kr G4 E
G5 D
G6 M
25 cm
16
15
17
21
21
17
50 cm
31
25
25
37.7
38
34.3
75 cm
50
48
51
51.6
53
51
100 cm
64
59
64
65.7
70.3
65
150 cm
92
86
91
94.7
92
94.3
4th hour
Table:
The effect of drop height on the bounce height of a tennis ball
Height
Dropped
25 cm
50 cm
75 cm
100 cm
150 cm
Height Ball Bounces
G1 J
15.7
31.3
51
65.7
92.3
G2 M
17
31.7
49
66
89
G3 B
20
34.7
52
69
97
G4 K
G5 A
12.7
32
51.7
65
89
17.7
34.7
50
66.3
96.3
Graph
The effect of surface on the bounce height of a tennis ball
 First Paragraph:
 In your own words describe the purpose of the experiment.
 Second Paragraph:




Restate your hypothesis and your reasoning for this prediction.
Summarize the lab procedure.
Explain the setup of the lab, control/variable, etc.
Describe safety precautions.
 Third Paragraph:
 Describe the outcome of the experiment and whether your
hypothesis was supported or rejected by the data.
 refer to your data tables, graphs, etc. in assessing the data
 trends or patterns that support your conclusion.
 Conclusion:
 explain exactly what was/was not accomplished or learned
 Give a detailed description of how you were able to determine the
above.
 Explain hidden variables that may have affected the reliability of
the data
 Suggestions for improving the reliability of the data?
```