Lab Report Sample – Comprised of sections from a number of exemplary student lab reports
Integrated Science 1
9/15/2014
A. Title
The effect of the number of drops of rubbing alcohol on the amount of bacterial growth
B. Introduction/Purpose
Solar panels are composed of photovoltaic cells that convert sunlight into electricity (EERE, 8/12/11).
They are used all over the world and are gaining popularity since they make renewable and clean energy. They
work wherever the sun is shining and, because of this, are very portable. When photons from light hit the panel and
knock electrons on the material loose a current is produced, which is electricity (EERE, 8/12/11). Some photons
don't have enough energy to knock the electrons loose so no current is produced from these photons (EERE,
8/12/11). However, solar panels currently are not very efficient. Most household solar panels convert about 15% of
available sunlight into electricity (Northwestern, 4/23/13). This is because they don't use the full spectrum of
sunlight, only the visible light (EERE, 812/11). Visible light only makes up 7% of sunlight while ultraviolet and
infrared make up the majority (Solar Power Is the Future, 2013). Different wavelengths of light have different
amounts of energy and infrared and ultraviolet don't have the energy needed to create a current (Solar Power is the
Future, 2013). The color of light is a function of its wavelength and smaller wavelengths are more intense. Longer
wavelengths move slower and produce the colors in the beginning of the visible spectrum such as red, orange, and
yellow. A violet light will turn into a red light eventually because over time it will slow down due to forces such as
gravity in the universe (Solar Power is the Future, 2013). Since different colors are different wavelengths, some
colors will produce more electricity since they have more energy.
This experiment is being done to find out if the age of someone affects how they do on a Stroop Effect test,
therefore testing if age affects performance, intelligence, and reaction time. People who might be interested in this
experiment are neurologists (because it tests two different parts of the brain to see which one responds first),
psychologists, and just people who are interested in neuroscience and psychology. When Stroop first came up with
the Stroop Effect in 1935, many people were interested in it, and even today it is still a popular psychology test.
This test is important, because it can help determine if age really is a factor in intelligence and reaction time.
I predict that the baseball with seams that are 0.2 cm high will fly faster than a ball with 0.3 cm or 0.4 cm
high seams (with the same amount of force applied for each test). I think this is true because there is less resistance
on the lower seams and therefore the ball won’t get slowed down as much and will fly faster. Also there is a reason
for the lower seams in higher levels of baseball and it is that as you get in higher levels, the importance goes from
just being able to throw a strike to having to throw the hardest you possibly can (Hoefs, April 29th 2012). So it only
makes sense that, as you need to throw harder you lower the seams meaning lower seams equals harder throws. In
an experiment done in 2006 by students at LSU they tested the effects of seam height on accuracy of pitchers and
concluded that the higher the seams the more accurate the throw because the lower seams wouldn’t grip and would
fly off more uncontrollably resulting in a less accurate but faster throw (LSU Baseball, 2011).
C. Hypothesis
If the lowest point of the catapult arm is three vertical centimeters from the ground the object will travel its
maximum distance.
D. Materials and Procedures
Materials
• 15 Shooting Strings
• 15 feet of nylon
• 4 leathers
• A 10 diamond mesh
• A spool of sidewall string
• A 6 diamond mesh
• A 30” lacrosse shaft
• A speed gun
• An unstrung lacrosse head
• A partner
• A bucket
• A lacrosse goal
• Warm Water
• 15 lacrosse balls
• Scissors
• A mode of transportation (car)
• A lighter
Experimental Set Up Procedure:
1. Gather necessary materials
2. Once materials are collected locate a 1 meter dropping point
3. Prepare Parachutes by looking at lab or parachute construction directions
4. Keep one parachute its normal length (17 cm)
5. With the second parachute cut 1 inch off of each end.
6. The total length on the top should be 15 cm.
7. Repeat for the third parachute only cut 2 inches off each side
8. You should have 3 parachutes with the lengths 17.15, and 13 cm
Data Collection Procedure:
1. Place stop watch into hand and get ready to get the speed
2. Drop the 1st parachute (17 cm)
3. Make sure bottom of parachute is at the top of the tape mark
4. With the stop watch, record the time it takes to get to the ground from the ledge
5. Record data for both the quantitative and qualitative data tables
6. Repeat 3 times until all trials are finished for the smallest parachute
7. Then with the medium sized parachute (15cm) drop from top of tape mark
8. Repeat steps 3-6 for the next level of IV
9. Then follow steps 3 – 6 for the shortest parachute (13 cm)
10. Calculate the average amount of time taken for each length of parachute to drop
11. Return materials and clean up work station
Experimental Design:
The independent variable for this experiment is different fat contents in chocolate. The levels of
I.V. are white chocolate, dark chocolate both 60% and 80% cacao, and milk chocolate with 20% and 30%
cacao. There are two trials per chocolate type. The quantitative variable in this experiment is melting time
and the qualitative variable is the taste of the chocolate after being melted. The constants include same
temperature, same chocolate for trials, same room, same weather, and same surface.
E. Data/Results
Type of Food vs. Protein Content in Grams
IV.
DV.
Type of Food
Grams of Protein
Trials
1
2
Mean Grams of Protein
3
Meats
Grains
Dairy
Vegetables (control)
Fats and Oils
Protein Content vs. Sweetness of Food
IV.
Type of Food
DV.
Sweetness of Food (not, mild, very)
Trials
1
2
Mode Sweetness
3
Meats
Grains
Dairy
Vegetables (control)
Fats and Oils
Size of rotor vs. time to reach floor in seconds
1.29 1.27 Time in second
1.22 Average speed of free fall 1.17 1.12 1.07 1.07 17 cm 1.08 15 cm Size of rotor (cm) 13 cm F. Discussion
In the experiment, we found varied results. The mean distance the die traveled before hitting the ground
ranged from 12 cm to 48 cm. The plastic spoon went the farthest, its mean 47.3 cm. The metal spoon catapulted the
die to 9.3 cm, the ice cream scooper got it to 12.6 cm, and finally, the wooden spoon helped the die go to 21.6 cm.
For the sound the catapult makes, we discovered that the plastic spoon, our control, made a soft sound, the metal
made a metal clicking sound, the ice cream scooper, created loud ceramic whacking, and the results for the wooden
spoon were so diverse that we couldn't come up with a mode. Some of the data was quite unreliable, especially for
the wooden spoon and ice cream scooper. It was almost impossible to wrap the same rubber band the same number
of times on the plastic spoon, whose arm is less than a centimeter thick, as the ceramic ice cream scooper, whose
arm was more than 5 centimeters thick. Additionally, the length of the wooden spoon extended far off the end of
the table, weighing the catapult down. The small stapler remover wasn't strong enough to fully catapult with these
spoons. We ended up getting data, but the reliability is definitely questionable. The staple remover wasn't as strong
as we expected, and our data was not what we thought it would be. The plastic spoon seemed weak and flimsy; it
ended up hurling the die much, much farther (47.3 cm, more than 25 cm farther than the 2nd farthest) than any of
the other spoons. This really surprised all of us.
We got these results that we did because hand sanitizer can eliminate bacteria in the highest numbers. The
hand sanitizer needs at least 60-95 percent of alcohol to kill off all the bacteria but that much alcohol isn't good for
your skin (Franklin, March 21, 2006). Hydrogen peroxide works also works well in killing bacteria, since when the
H202 (hydrogen peroxide) hits oxygen it releases a substance that kills off all the bacteria, making it so there will
be no more bacteria growth (How Does Hydrogen Peroxide Kill Bacteria?, May, 4,2014). Since Formula 409
spray is primarily used to clean floors, it worked the worst. This shows that it’s not the best spray to clean up
counters or floors with. Finally, if hand soap is antibacterial that means that is will kill off 99.9 percent of the
germs, viruses, and or bacteria (Chameides, November 9th, 2012). Our findings were in line with our research
about hand sanitizer, hydrogen peroxide, and Formula 409.
To make this experiment more successful we should sterilize everything so there are no bacteria on any
objects used in the experiment. We also should not have not left the petri dish open as long, since the auger ws
probably exposed to bacteria. I think it would also work better if I let the petri dish that was growing bacteria in the
incubator sit longer so it would have more bacteria on which to experiment. Also, instead of just wiping of the
cleaning supplies with a piece of paper in the procedures I should of washed if off to make it more sanitized. In
order to study this topic further, I would be interested in identifying if bacteria, fungi, or protozoans respond the
most to different cleaning supplies in order to test the “all purpose” claim of many cleaning products.
G. Conclusion:
The purpose of this study was to discover how certain factors, such as sleep in the case of this specific
experiment, affect the fitness level of people, in the form of their Harvard Step Test fitness score. The data showed
that getting eight or more hours of sleep per night, or even the minimum six, as suggested was needed by the
background research, is actually not a factor in making up one's cardiovascular fitness level. This completely
disproved my hypothesis that if someone get's less than six hours of sleep per night, then they will be less fit as
measured by the Harvard Step Test than those who get more than six hours per night. Contrary to the hypothesis,
those who got less than six hours of sleep were actually equally or more fit than those who got more than six hours
of sleep per night. This might have been the case because, although sleep is an important factor in someone’s
fitness, a lot of other things are also critical. As mentioned in the Daily Harvard Journal, “fitness can only be
measured in individuals who have the same diet and same amount of daily exercise” (August 2009).
H. Bibliography/References Cited:
Benson, Tom. “Terminal Velocity (gravity and drag).” NASA.gov. September 17, 2011.
http://www.grc.nasa.gov/WWW/k-12/airplane/termv.html
Greene, Nick. “Gravitational Pull.” About.com. September 17, 2011.
http://space.about.com/od/glossaries/g/gravitationpull.htm
Henderson, Tom. “Newton’s Second Law of Motion, Free Fall and Air Resistance. ”The Physics
Classroom. September 17, 2011. http://www.physicsclassroom.com/class/newtlaws/u2l3e.cfm