Lab Report 8-physics PDF

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Section 08: Sliding on an inclined plane

Lab report 08: Newton’s laws on an Inclined Plane

University of Texas at El Paso

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Section 08: Sliding on an inclined plane

2 Introduction

Newtons second law states that, “the acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force, and inversely proportional to the mass of the object”(Physics classroom). This law can be applied to an object in motion on an inclined plane because it has the forces of Weight, which is straight down, Normal force, which pushes perpendicular to the incline, and Friction which acts parallel to the incline. Using the angle of the inclined plane we can find the perpendicular and parallel components of weight such as 𝐹𝑔⟂ = 𝐹𝑔𝑐𝑜𝑠θ, 𝐹𝑔∥ = 𝐹𝑔𝑠𝑖𝑛θ , respectively. This will be utilized in Newton’s second law to solve for the coefficient of kinetic and static friction for the object, in this experiment it is Albert Einstein, on an inclined plane. The coefficient of friction is defined as the ratio of the force of friction to the normal force, µ = 𝐹/𝑁 . For kinetic, µ𝑘 = 𝐹𝑘/𝑁and for static, µ𝑠 = 𝐹𝑠/𝑁.When an object is static and not moving, this means that the applied force is equal to the force of static friction. Materials and Setup ● Computer Access ● Pivot Interactions ● Protractor ● Calculator ● Ruler ● Stopwatch

Section 08: Sliding on an inclined plane

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The protractor on Pivot interactions allow us to take the angle of the inclined plane and use this value to solve for the static and kinetic frictions. Stopwatch and ruler will be used to find the total displacement and time which will be used in newtons second law formula to solve for the coefficient of kinetic friction. Procedure To begin the experiment pivot interactions were started and the video of Einstein on the Ramp was played twice. A protractor was added and placed on top of the surface and the video was played until the moment right before Einstein made a movement, and the angle was recorded. Next, a ruler was placed parallel to the ramp and a stopwatch was added and reset to the moment right before einstein slid down. Einstein’s position and time was recorded until he reached the end of the ramp, and graphed. Data and Data analysis

Figure 1. Position(cm) vs time(s) of Einstien down a ramp at 24 degrees

Section 08: Sliding on an inclined plane

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(Mass)(Gravity)(sin(angle))/((Mass)(Gravity)(cos(angle))=µ𝑠 Equation 1. Coefficient of Static Friction (Gravity(sin(angle))-acceleration)/((Gravity(cos(angle)))=µ𝑘 Equation 2. Coefficient of Kinetic Friction 𝑎∥ = 2∆𝑑 /∆𝑡

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∥

Equation 3. Newtons second law. Acceleration of the parallel Figure 1 show the position and time of einstein moving down a ramp. We can see that the velocity is non-constant as the shape of the line shows it is increasing. As said in the introduction the coefficient of static friction=Friction loss/normal force. Since the object is static the Force of the object going down the ramp is equal to the friction loss. Therefore the force going down/normal force= coefficient of static friction. The coefficient of static friction is shown in Equation 1. And is solved by using trigonometry and the angle right before einstein moves. The mass is unknown so I put 1, and the angle is 24 degrees which gives a static friction of 0.445. Using Equation 3, I found the acceleration to be -.112m/s^2, the acceleration is negative because it is moving in the negative direction (downward). This accelrartion was plugged into Eqaution 2 and was solved to be 0.432, the coefficient of kinetic friction. Conclusion The results, µ𝑠 = 0. 445, µ𝑘 = 0. 432,make sense because generally, the coefficient of static friction is always greater than the kinetic friction. This means that in this experiment there was more forces working to keep albert einstein in place than there were forces working to resist

Section 08: Sliding on an inclined plane

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einstein going down the ramp. When the object was able to move, in that instant, the applied force became greater than the normal force acting on albert einstein. Personal Learning Experience In this lab, I learned that in every movement we make whether its ourselves or an object it always requires force. I always wondered why some objects wouldnt move when I pushed them but its because my force was not stronger than the friction of the objects static friction. To be able to move this object I needed to apply a stronger force to overcome the static friction. I also realized the hardest part when you push an object is getting it to move but once it moves its easier to continue moving and not as hard as moving it from its static position.

Section 08: Sliding on an inclined plane

6 References

Inclined Planes. (n.d.). Retrieved June 26, 2020, from https://www.physicsclassroom.com/class/vectors/Lesson-3/Inclined-Planes...