Problem Solving
Part A: Center of Mass in One Direction
1. Since the mass of the plate is a uniform, the center of mass is in the center of the plate. The plate has diameter d = 28 cm, thus the center of mass is 14 cm from the edge of the plate. In the lab, two scenarios will be analyzed; 1) when the glass is standing up, and 2) when the glass is laying on its side. When the glass is standing up, its mass is uniform about the axis of symmetry. Therefore, the horizontal center of mass will be at the exact midpoint between the two sides of the glass. The radius of the glass is 4 cm, thus the horizontal center of mass, when the glass is standing up, is 4 cm from the edge of the glass. On the other hand, when on its side, because the mass of the glass is not uniform, that is two-thirds of the mass is in the base, the vertical center of mass has to be calculated using the equation xcm=miximi, where mi is the mass of the ith component and xi is the distance away from the origin the center of mass of the ith component is. For a glass 8 cm in diameter, 16 cm tall, of mass 300 grams (two-thirds of which is in the base), whose base is 3 cm tall and is at the origin, the vertical center of mass is xcm=miximi=200g1.5cm+100g(6.5cm)(300g)=4.17cm. The vertical center of mass is located 4.17 cm from the bottom of the glass. 3. Because the waiter's hand has a diameter d = 20 cm, the range of points above the waiter's hand that can support a center of mass is 10 cm. 4. The center of mass of the tray plus one glass--with the origin at the center of the tray--given as a function of time, is xcm=mtxt+mgxgmt+mg=500g0+300gxg500g+300g=300xg800=38xg. 5. The farthest from the center of the tray a glass--when standing up--can be is 38xg=384 cm=1.5cm. Because the waiter's hand can support a center of mass up to 10 cm from the center of the tray, the distance a glass can be from the...

...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...

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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...

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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...

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“The Domino Effect”
Teacher’s Prompt
Investigate the domino effect with a set of dominoes.
Aim
To investigate the relationship between the mass of the dominoes, and how it impacts the time taken of the domino effect.
Independent Variable: The mass of each domino (12.38 g, 32.38 g, 42.38 g, 62.38 g, 82.38 g).
Dependent Variable: Time taken of the domino effect.
Controlled Variable: The number of dominoes used (8 dominoes), the distance between the dominoes (2 cm), the loads used as the initial force applied on the domino (50g), the inclined plane used as a platform that will direct the load to hit the first domino (20o), the stopwatch used to time the domino effect, the person using the stopwatch, the person releasing the metal weight from the top of the inclined plane, the ruler used to measure the distance between the dominoes.
Equipment
1 Inclined Plane
1 (50 g) Metal Weight
4 x 8 (20 g) Metal Weight
8 Dominoes (Uno Stackos)
1 Digital Mass Balance (± 0.01 g)
1 Masking Tape
1 Protractor
1 Ruler
1 Stopwatch (± 0.01 s)
-34290039687500Diagram
Analysis of Variables
Independent Variable:
The mass of the dominoes will vary ranging from 12.38 g to 82.38 g. The increase between each of the variable will be constantly 20 g, to satisfy the range of the mass; the original mass of the domino is 12.38 g, and an additional mass from a 20 g of load will be attached on top of the domino for every change in variable.
Dependent Variable:
In accordance to...

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Free Fall
Rachel Shea
Physics 131 Lab, QL
Hasbrouck 210
Sept. 21, 2014
Abstract
This experiment measures the study of motion by observing the force of gravity acting solely upon an object, and also measures reaction time. If an object is in free fall, the only force acting upon it is gravity. The object used in this experiment was a golf ball that provided some acceleration when dropped. A sensor positioned underneath a table recorded the golf ball’s pattern of motion, when dropped. The main objective of performing this experiment is to measure the velocity and position of the ball to eventually find the acceleration of free fall. A computer program called, DataStudio, was used to create a graph of position vs. time and a graph of velocity vs. time. The second part of the experiment involved randomly dropping a ruler and having your partner catch it to determine reaction time.
Questions
1. The parabolic curves open upward instead of downward because of the golf balls movement over time: where it is dropped from, to where it ends up. The ball begins close to the sensor, then drops to the ground, then bounces back up closer to sensor again, therefore the bounces correspond with the bottom curves of the parabola. If the data were collected from the floor then the curve would open downward. But because the sensor graphs the position from the sensor, the curve was upwards.
2.
-4572009207500
The slope of the velocity versus time graph...

...accident such as car crash, since the momentum changes instantly, the force becomes extremely great. Impulsive force is produced during the collision and it will cause severe damage to the car, and may also injure the passengers in it. 3 The passengers’ momentum can be stopped by objects in the car such as dashboard, side door, or windshield, however, it will cause serious injuries because the force would be very great. To increase the safety of the driver and the passengers, safety devices such as seatbelts, air bags, crumple zones, and etc. are introduced. Safety devices such as seatbelts, air bags, crumple zones and etc are designed to reduce the forces on the body if there is a collision. These safety devices are mostly made based on the physics principle of force and momentum, which is
This relationship says that if momentum is transferred over a longer period of time, the force involved is less. If the force of a collision can be reduced, then the chances that someone would get hurt in an accident are lower.4 Since momentum cannot be transformed to another form of energy, it is always conserved during any collision. The change in momentum is then a fixed quantity, and to lower the force, changes have to be made in the time of the collision.5 The time required for the car to stop in a collision have to be increased so that the forces that will impact the occupant will be lower, and they will be less likely to be hurt. If the time taken for the change...