Introduction
The purpose of this lab was to investigate how the orientation of a particular object affects the coefficient of friction and how to calculate the coefficient of friction and calculate it.
The question we are trying to answer is: If I change the orientation of the object on different surfaces what will happen to its coefficient?
Hypothesis
When the orientation of the object is changed from standing up to laying down the coefficient of friction will changed. When the surfaces is changed the coefficient of friction will change. Variables:
Independent Variables: Different surfaces, orientation of the weight
Dependent Variables: Coefficient of friction
Control Variable: Weight
Methods and Materials
Materials:
Foil
Wood
Plastic
Paper
Wax Paper
Weight
Ramp
Protractor
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What factors seem to cause a small coefficient of friction? Explain.
Ans.
Objects that tend to weigh less move more easily, so if in this experiment we put a marble instead of the weight. The marble would move quickly with a lower angle thus causing a small coefficient of friction. Also a round object would move quickly so that would result in a lower coefficient also.
Q4. What materials did you use to get the lowest and highest coefficient of friction? Explain why you think that these materials have either low or high coefficients.
Ans.
We only used one material which was the weight in this experiment. The weight had a smooth surface which may have allowed it to slip easily compared to a material that has rougher sides. An object with a smoother surface has less friction and when gravity acts upon it, it will slide easily thus at a lower angle causing a low coefficient.
Q5. Why is the tangent of the angle at which the object starts to slip equal to the coefficient of friction?
Ans.
The tangent of the angle at which the object starts to slip is equal to the coefficient of friction because of this equation: μ = mg(sinθ)/mg(singθ) = sinθ/cosθ = tanθ μ = tanθ
Contents TASK 1 1 1.1)TYPICAL AXIS CONVENTION 1 1.2) operations of types of drives and axis control system. 4 1.3) SIX DEGREES OF FREEDOM. 8 1.4] WORK HOLDING DEVICE FOR LATHE 8 TASK 2. 12 2.1) Assess the suitability of machine tools for the production of following components 12 2.2) SEQUENCE OF OPERATIONS TO PRODUCE THE GIVEN COMPONENT 13 2.3) MACHINING AND FORMING PROCESS 13 TASK 3
The coordinates of the system is defined by , θ = angle of the chassis from vertical, α = angle of tread assemblies from vertical, Ø = rotation angle of tread sprockets from vertical, mc = mass of chassis, mT = mass of tread, ms = mass of sprocket, Lc = length from centre of sprocket to centre of chassis, LT = length from centre of sprocket to centre of tread assembly. The kinetic energies of the sprocket, chassis and tread assemblies are given respectively , T_S=1/2[m_c x ̇^2+J_S φ ̇^2] (1) T_C=1/2 [〖m_c (x ̇-L_c θ ̇ cosθ)〗^2+m_c (〖L_c θ ̇ sin〖θ)〗〗^2+J_c θ ̇^2 ] (2) T_T=1/2[m_T (〖x ̇-L_T α ̇ cos〖α)〗〗^2+m_T (〖L_T α ̇ sin〖α)〗〗^2+J_T α ̇^2] (3) The gravitational potential energy is given by ,
An independent variable is the weight. The dependant variable is the speed. Some control variables are the track, wheels, and body style. Three different pinewood derby masses were tested in the experiment. 140g, 173g, and 204g. Each weight division was tested 3 times.
In conclusion, the dime was able to pull it off and hold more drops than the penny. My hypothesis was incorrect because, I thought the penny would hold more drops than the dime because the penny was bigger and I thought it would absorb more. But the dime held more. Preston and I even ran the tests or investigation three times for each coin. The one question I had was ,what if the penny was stacked 1 time and the dime was stacked one time,would it make a difference ?
Friction- Friction is the resistance of an object against a surface. (ex. Unexpectantly pressing on the brakes of your car) 6. Traction-
In the first activity, I determined the circumference and tangential speed of points on spinning DVDs to demonstrate the rotation curve of a rigid body. For instance, the DVD with a radius of 4 has a circumference of 25.13 cm and a tangential speed of 1933.08 cm per second. During the activity, I noticed as the radius increased, the tangential speed also increased. I also noticed the shape of the rigid body rotation curve was linear.
These factors include the size and shape of the object. For example, the shape and size of paper of a rock differs from that of paper. But paper, because of it shape and size, would float down slower with more air resistance than the rock which has less air resistance. For example, in a well known article on the fall of an object, states, “More massive objects will only fall faster if there is an appreciable amount of air resistance present” (The Big Misconception 1). This shows the fall of an object does not care about mass but size and shape.
How does the type of dissolvent in the water affect the number of drops that can fit on a penny? We will attempt to find the answer to this question using the hypothesis “If we use salt water solution, then there will be more drops on the penny. ” We will use the materials salt, sugar, lemonade mix, flour, a beaker, a pipette, paper towels, a stirring rod, a graduated cylinder, and some tap
This in turn does not add a greater gravitational pull downward due to the greater level of mass. Which means that the string has added tension, which pulls the cart faster in table number 2. How does the acceleration in Data Table 3 compare with that of Data Table 1? Why do we observe this difference?
If we wanted to pick up something, it would slip from our hands. If we wanted sit down, we would fall over. We wouldn’t be able to create or invent anything without friction because whatever we create requires friction. Imagine a day of just you falling over and over again; do you think you would be able to accomplish anything on a day like this? Nothing would be at the same place if friction
Modeling of Contact Angle for a Liquid in Contact with a Rough Surface When a solid is in contact with liquid, the molecular attraction will reduce the energy of the system below that for the two separated surfaces. This is expressed by the Dupré equation Figure-1 2.1 Wenzel Model: The Wenzel model (Robert N. Wenzel 1936) describes the homogeneous wetting regime, as seen in Figure 2, and is defined by the following equation for the contact angle on a rough surface. where is the apparent contact angle which corresponds to the stable equilibrium state (i.e. minimum free energy state for the system). The roughness ratio, r, is a measure of how surface roughness affects a homogeneous surface.
F. How close was your calculation of the value of g at your location? What might be a few sources for error in your experimental data and calculations? All of my calculations were close to the accepted value of gravity. A few of my calculations were further off, but most were very close.
In the experiment our group had the option to change the mass of the ball of clay or the height from where it was dropped. The option that was chosen was to change the height from where the clay was dropped. We balanced the ruler on the lincoln log to then placed the minion on one side of the ruler. We stood the meter stick upright, the zero being closest to the table. Then we made a ball of clay and dropped it from a specific height making sure not to change it.
Another way is, that gravity hastens the object’s downward movement until it gets to the ground. It does this because gravity keeps you from floating into space by pulling you down
The edge may be unitary or produced from materials which allow for height or length modification. In one picture the upper features of the tool facing the user are twisted between 5° to 20°. In an ideal embodiment, the primary support bar is inclined at between 8° and 12°. In a more preferred embodiment, the central support bar is tilted at 10°.