Torque and Equilibrium
Purpose: Apply principle of static equilibrium to determine a coefficient of friction. Research Question: What is the coefficient of friction between a meter stick and wall? Hypothesis: Tying a piece of string on to the end of a meter stick, put the other end of the meter stick against the wall so that the meter stick is horizontal and does not slide down the wall. Hang a weight on the meter stick sliding it to a point where the meter stick is about to come off from the wall.

Data:
Θ = 43
Center of mass of meter stick: 0.5 m
Length of meter stick: 1 m
Mass of meter stick: 0.0842 kg
Location of weight: 0.83 m
Mass of weight: 0.5 kg

Evaluation of Data:
∑Τ =0 = mgr0 + wr1 – T*r2sin Θ
= .0842*9.8*.50 + 0.5*0.83*9.8 – T *1 sin 43
= 6.57 N = T

∑Fx = 0 = FN – T sin Θ
= FN – 6.57* cos 43
= 4.804 = FN

∑Fy =0= Ff + T sin Θ – mg-W
= Ff + 6.57 sin 43 – 0.0842*9.8 – 0.5*9.8
=1.24 N = Ff

µ = Ff/FN = 1.24/4.804 = 0.26

Percent Error: Error could have resulted from the holes in the wall since they were made from brick. The string that was attached to one end of the meter stick as well as the wall tended to move because the tape did not hold well.

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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...

...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...

...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...

...
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...

...The Relationship Involving Acceleration, Net Force, and Mass
Giho Park
Purpose
The purpose of this lab investigation is to observe the relationship among the net force, mass, and acceleration of an object.
Hypothesis/Prediction
Part A
If the net force increases with a constant mass,
then the acceleration would increase,
because the force would push the object to increase the velocity.
Part B
If the mass of the cart increases with a constant net force,
then the acceleration would increase
because the greater inertia of the object would cause the acceleration to decrease.
Materials
ticker timer, ticker tape, cart, masking tape, one 2-m board, marker, ruler, spring scale, three 100-g masses, two 1.0-kg masses, string,
Procedure
Part A: Acceleration and Net Force
1. Verify that the equipment you intend to use is functioning properly.
2. Measure the mass of the cart and record it in the observation table.
3. Set up the apparatus so that the least net force will act on the cart. Allow the motion to occur and obtain the data required to find the acceleration α1.
4. Repeat the procedure with an increased net force. For example, you can transfer one of the 100-g masses from the cart to the string hanging over the pulley. This allows the mass of the system to remain constant. Determine the data for α2.
5. Repeat the procedure with the highest net force to determine the data for α3.
Part B: Acceleration and Mass
6....

...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...

...static friction force vs. the normal force is .391. The slope is the coefficient of static friction. It is found by dividing (largest average – small average)/ (largest normal force – smallest normal force). Since it’s impossible to divide by zero, Fn can’t equal zero which means that a line fitted to these data can’t pass through the origin. The coefficient can also not have a value of zero.
7. See graph. The slope if the coefficient of kinetic friction. It is found by dividing Fn from Fk. Since it is impossible to divide by zero, Fn can’t equal zero which means that a line fitted to these data can’t pass through the origin. The coefficient can also not have a value or zero.
8.
Conclusion:-
In conclusion, the purpose of this lab was to determine the relationship between the force of static and kinetic friction and the weight of an object. We did this by using a block of wood and a set of weight. By using a motion detector and force sensor, we were able to determine the forces of static and kinetic friction of the block with and without weights. For part II, we completed many trials pulling the block with various weights on it across, increasing the weight with each set of trials. From doing this we measured the forces of the kinetic and static friction for each weight. For part III, we pushed the block with and without on additional mass of 500g across, this time measuring the acceleration. We were able to calculate the coefficient of kinetic...