Purpose: The Purpose of this experiment is to find the width of a piece of hair using diffraction pattern created by a thin film.

Hypothesis: If the hair is human it will have a width of 10-4m.

Procedure:
1. Place two pieces of glass flat against each other.
2. Obtain a piece of long hair, most likely from one group member’s head. 3. Place the hair between the sheets of glass on one edge. 4. Place a rubber band around the pieces of glass on the side opposite the hair for stability. 5. Measure the distance between the hair and the opposite edge of the glass. 6. Using a millimeter ruler measure the length of one dark spot in the diffraction pattern. 7. Measure out a cm on a piece of paper, mark it, and place under the glass. 8. Line the edge of the hair with the beginning of the cm and count how many times the diffraction pattern repeats (the number of dark spots/ cm). Observations:

• The diffraction pattern was very difficult to see.
• Counting of lines in a cm may have been off due to the barley visible diffraction pattern. • Before the hair was placed between the glass, there was already somewhat of a diffraction pattern visible. Data:

Length of glass to the hair: 6.4cm±1cm
Wavelength of light: 550nm
Lines per cm: 15 lines
Length of one dark spot: .0667cm
m = 191

Calculations:
M:
15*6.4=96±1
96*2=192 ±1 (light bands also accounted for)
192-1= 191±1 (band touching the axis does not count)
m = 191

2t=mλ (destructive interference)
t = mλ/2
= 191±1 (550x10-9) / 2
t = 5.25x10-5 m ±1cm

Conclusion:
In this experiment we found that the width of the hair was 5.25 x10-5 m ±1cm. This proved my hypothesis of 10-4m incorrect, but was very close. Considering that the width of hair varies from person to person and hair to hair, this number seems appropriate. During the experiment we found there were 15 dark lines in one cm of the diffraction pattern created by the hair. This then...

...
Centro de investigación y desarrollo de educación bilingüe (CIDEB)
PhysicsLAB REPORT
Uniform Rectilinear Motion
Teacher: Patrick Morris
Alejandra Castillejos Longoria
Group: 205
ID: 1663878
Abstract
The purpose of this experiment, was to prove the concept of the uniform linear motion by using an air track. With this, we demonstrated the impulse and change in momentum, the conservation of energy and the linear motion. We basically learnt to calculate the distance/time, acceleration/time, and velocity/time and graph it. The air track is also used to study collisions, both elastic and inelastic. Since there is very little energy lost through friction it is easy to demonstrate how momentum is conserved before and after a collision. According to the result, the velocity of the object in the air track was constant, it means that it didn’t have acceleration because it has constant velocity.
Introduction
First of all; we should understand what is linear motion. Linear motion is motion along a straight line, and can therefore be described mathematically using only one spatial dimension. Uniform linear motion with constant velocity or zero acceleration. The Air Track can be used to obtain an accurate investigation of the laws of motion. A car or glider travels on a cushion of air provided which reduces friction. Since the friction is all but removed the car will be moving at...

...APPhysics Slinky Velocity Lab
Group: Asaf Yankilevich, Lily Greenwald, Yaeli Eijkenaar, Michal Antonov
2/23/15
Materials
● Slinky
● Spring weight
● Force measurer
● Measuring Tape
● Timer
Procedure
1. The first slinky’s mass was weighed, using a scale, and its tension was measured using a
force measurer
2. The slinky was stretched to 4m.
3. The linear mass density was solved for, by dividing the mass by the length.
4. The theoretical velocity was solved for, using the equation v =
√
Force Tension
μ
5. The process was then repeated for a different length (6 m).
6. The actual velocity was then tested by stretching out the string to the preferred length (4
m) and it was moved side to side to create a longitudinal wave and the period was
measured. The spring was then moved up and down to create a transversal wave and the
period was measured.
7. The process was repeated for 6 m.
8. The periods of the experiments were used to find the actual velocities using the equation
v = d/t.
Calculations
0.61kg slinky
4 meters
μ = m/L = 0.61/4 = 0.1525 kg/m
Theoretical: v =
√
Force Tension
= √1.9/0.1525
μ
= 3.53 m/s
Actual: v = d/t = 8/2.5 = 3.2 m/s (for both longitudinal and transverse)
6 meters
μ = m/L = 0.61/6 = 0.1017
Theoretical: v =
√
Force Tension
= √2.4/0.1017
μ
= 4.86 m/s ...

...Hair Conditioner Lab
Intro
The hair industry has been been devoted to answering a need of our american people for years. A
market mainly targeted towards women, the search for products that will soften, repair,
rejuvenate, enlarge, and even strengthen hair is unending. The question that we posed for this lab
was: Does hair conditioner really actually strengthen hair as it promises?
Materials
Conditioner
Plastic cup
Forceps
Hair (from Nate, Alyssa, Makenna, and Lisa)
Microscope
Water
Pipette
Glass slides
Cover slips
Sharpie
Towels
Spring scale
Video camera
!
Methods
Conditioner was chosen that promised to strengthen and visibly repair hair. To try to observe any
physical differences, a sample was taken from my hair before it was conditioned, and after. Both
samples were removed with forceps and included many strands of hair. To condition the hair, the
directions were followed on the conditioner bottle to ensure that the products directions would
give the promised result. My hair was rinsed thoroughly, then generously massaged with the
conditioner, which was left in my hair for 15 minutes as directed. Then, all of the conditioner
was rinsed out of my hair and was dried with towels. Then, forceps were used to remove the
conditioned...

...Name ___Anjad Itayem_______________ Blackbody Radiation Lab 11
Go to http://phet.colorado.edu/simulations/sims.php?sim=Blackbody_Spectrum
and click on Run Now.
1) In this lab, you will use the Blackbody Spectrum Simulation to investigate how the spectrum of electromagnetic radiation emitted by objects is affected by the object's temperature. In this simulation, you can input the temperature and observe the spectrum of the radiation emitted.
a) The temperature of stars in the universe varies with the type of star and the age of the star among other things. By looking at the shape of the spectrum of light emitted by a star, we can tell something about its average surface temperature.
i) If we observe a star's spectrum and find that the peak power occurs at the border between red and infrared light, what is the approximate surface temperature of the star? (in degrees C)
Using the Spectrum Simulator, I found that this border is in the neighborhood of 4045 Kelvin, which converts to approximately 3772o C
ii) If we observe a stars spectrum and find that the peak power occurs at the border between blue and ultraviolet light, what is the surface temperature of the star? (in degrees C)
Using the Spectrum Simulator, I found that this border is in the neighborhood of 7080 Kelvin, which converts to approximately 6807o C
b) Light bulbs operate at 2500 degrees C.
i) What is the wavelength at which the most power is...

...
PhysicsLab Report
How does the length of a string holding a pendulum affect its oscillation?
Method
1. You will need the following apparatus: a pendulum, a piece of string, a clamp, a clamp stand and a timer.
2. Measure out 20cm and attach the metal ball.
3. Establish an angle and let the ball swing for 10 oscillations, timing it and stopping at the 10th one.
4. Write down your results.
5. Repeat steps 2-4 another 2 times so that your results are reliable.
6. Then change the length of the string 4 times, so that you get 5 different sets of results and for each time, repeat it 3 times.
DCP
Raw Data
Data Processing
Calculations:
To find the average of the time, I added all 3 values and then divided by three. For example:
(0.89+0.83+0.89)/3 = 0.87
I calculated the absolute uncertainty by considering the furthest point from the mean. For example:
1.31 (mean) – 1.25 (furthest point from the mean) = 0.06
Therefore my absolute uncertainty is +/- 0.06
I calculated the percentage uncertainty by dividing the absolute uncertainty by the mean and multiplying it by 100, like this:
(0.03/1.70) x100 = 0.18%
Source of uncertainties:
The uncertainties in the measurement came primarily from the equipment. Since we used a ruler that was divided into parts of 0.1cm, the readings were normally rounded up or down. The length of string was constant in all 3 times that we...

...trials were performed or if the class data were to be compared and averaged. Performing the experiments under a vacuum and frictionless setting would remove external variables that affect the data leading to more precise numbers. More accurate percent discrepancies illustrating laws of conservation can be achieved by adding more trials and including more sophisticated measuring tools. These techniques would lead to more accurate results to reduce any experimental errors and to better validate the concepts of energy and momentum conservation.
Conclusion
The purpose of the experiment was to investigate simple elastic and inelastic collisions to study the conservation of momentum and energy concepts. The objective of the lab was met since the validity of the Law of Conservation of Momentum was confirmed by determining the relationship of energy and momentum conservation between inelastic and elastic collisions by utilizing percent discrepancy calculations. The calculations state that the percent discrepancies for inelastic collisions were 8.75% and 19.23 % for the equal mass and unequal mass respectively. The percent discrepancies for the equal and unequal mass elastic collisions were 22.07% and 9.78 % respectively. Both of the percent discrepancies for the elastic collisions were close to the 10%-15% range which validates the concept of momentum conservation in inelastic elastic collisions. In regards to conservation of energy,...

... 9/16/14
Physics 01L
Density
Abstract
This experiment was conducted in order to determine the density of the Aluminum metal samples provided in the lab. Specific tools such as the vernier caliper and balance scale were used to measure and record the values found. Given that density is a measurement of mass over volume, both of these quantities would have to be determined experimentally, prior to proceeding with the calculation of the density, for each of the six subjects tested. Being as accurate and precise as possible, the data yielded a density that was similar to that of the accepted value for the density of aluminum. Taking averages of the measurements recorded by both partners may have introduced a variable for error. However, upon calculating the percent error of the results found, it was concluded that there was less than a three percent error, which supported the accuracy and credibility of the experiment.
Data
Table 1: Tabular Presentation
Aluminum
Diameter D1 (cm)
Diameter
D2 (cm)
Average
Diameter (cm)
Height
H1 (cm)
Height
H2 (cm)
Average Height (cm)
Mass (g)
Volume
(cm3)
1
1.27 cm
1.27 cm
1.27 cm
1.55 cm
1.548 cm
1.549 cm
5.6 g
V=1.96cm3
2
1.26 cm
1.266 cm
1.263 cm
2.64 cm
2.64 cm
2.64 cm
9.6 g
V=3.31 cm3
3
1.26 cm
1.266 cm
1.263 cm
4.726 cm
4.728 cm
4.727 cm
16.6 g
V=5.92 cm3
4
1.26 cm
1.268 cm
1.264 cm
6.218 cm
6.216 cm
6.217 cm
21.8 g
V=7.80 cm3
5...

...
Experiment 7: Relative Density
Laboratory Report
Marella Dela Cruz, Janrho Dellosa, Arran Enriquez,
Alyssa Estrella, Zacharie Fuentes
Department of Math and Physics
College of Science, University of Santo Tomas
España, Manila Philippines
Abstract
The experiment was conducted to show the different methods on how to determine an object’s composition through its density and to determine an object’s density by displacement method and the Archimedes Principle. Results show that. The materials used were the spring scale, beaker, 25 pieces of new 25 centavo coins, a bone from a pig’s leg, diet and regular soft drinks, and a pycnometer.
1. Introduction
Density is a physical property of matter. It is the mass per unit volume of a substance. In this experiment, relative density is also used to be able to determine the composition of the substances or objects used. Relative density is the ratio of a density of a substance to that of the density of a given reference material. It is also known as specific gravity. Density is used when making or building objects that are required to float such as ships on water and airplanes in the sky.
Objectives:
1. To determine the density of an object by displacement method
2. To determine the composition of a substance based on its density
3. To determine the density of a substance by Archimedes Principle
2. Theory
Relative Density (R.D.) or also known as Specific gravity (S.G.), is the raito of the density of...