What is the relationship between the cross-sectional area and the resistance of the resistor? Discuss in the context of your plot. If the radius of the given cylindrical resistor is twice as much, what would be the corresponding resistance?

/in /by

Lab 4 – Resistivity         Instructions & Data Sheet

Resistance of a resistor is modeled by the equation

(1)Where R is the resistance (Ω), L is the length (m), A is the cross-sectional area (m2), and ρ is a constant dependent upon the material called the resistivity (Ω-m). The length, thickness and material of a wire affects the resistance of the wire. Some materials have lower resistances than others. For example, the resistivity of Copper is 1.72×10-8 m (Ω-m) and is one of the lowest resistivities only second to silver. Nickel on the other hand has a resistivity of 7.8×10-8 m. The longer and narrower the wire, the higher the resistance. It’s harder for the electrons to move in a longer, narrow hallway.  Figure 1 gives a visual of a segment of wire and the quantities that are measured for resistance. In this lab, the values of length and resistivity are given.

Figure 1: A uniform cylinder of length l and cross sectional area A. The longer the cylinder, the greater its resistance. The larger its cross-sectional area A, the smaller its resistance. Image credit: Adapted from OpenStax College Physics. Original image from OpenStax, CC BY 4.0

 

Use the following link to complete the lab activity.

https://phet.colorado.edu/sims/html/resistance-in-a-wire/latest/resistance-in-a-wire_en.html

 

Part 1 – Vary the length keeping the cross-sectional area fixed

 

  1. Keeping the cross-sectional fixed at 7.50 cm2 and resistivity at 0.50 , vary the length 10 times, and tabulate length and resistance.
Length, L (cm) Resistance, R (
   
   
   
   
   
   
   
   
   
   

 

  1. Plot R vs L (i.e. R along y-axis and L along x-axis) on excel. Make sure to display the equation of the fit line and R2 Copy and paste it here.

 

  1. Equate the slope of the line to , and then calculate found experimental with the known value of to find %error.

 

 Part 2 – Vary the cross-sectional area keeping the length fixed

 

  1. Keeping the length fixed at 10 cm and resistivity at 0.50 , vary the cross-sectional area 10 times (starting with the largest area), and tabulate area, inverse area and resistance.
Area, A (cm2) Inverse Area, A-1 (cm-2) Resistance, R (
     
     
     
     
     
     
     
     
     
     

 

  1. Plot R vs A-1(i.e. R along y-axis and A-1 along x-axis) on excel. Make sure to display the equation of the fit line and R2 Copy and paste it here.

 

  1. Equate the slope of the line to , and then calculate

 

  1. Compare the found experimental with the known value of to find %error.

 

Part 3 – Conclusions

 

  1. What is the relationship between the length and the resistance of the resistor? Discuss in the context of your plot. If the length of the given resistor is twice as much, what would be the corresponding resistance?

Answer:

 

  1. What is the relationship between the cross-sectional area and the resistance of the resistor? Discuss in the context of your plot. If the radius of the given cylindrical resistor is twice as much, what would be the corresponding resistance?

Answer:

 

  1. A copper wire has a diameter of 0.5 mm and resistivity of 1.6 x 10-8Ωm. What will be the length of this wire to make its resistance 10Ω? How much does the resistance change if the diameter is doubled?

Answer:

An object is in free fall. At one instant, it is traveling at 46 m/s. Exactly 3.7 s later, what is its speed? The acceleration of gravity is 9.8 m/s?

/in /by

Answer in units of m/s.

An object is in free fall. At one instant, it is traveling at 46 m/s. Exactly 3.7 s later, what is its speed? The acceleration of gravity is 9.8 m/s?

 

How does the acceleration obtained from the experiment compare with the value you found using Equation 6. Report the acceleration obtained from your experiment along with its error.

/in /by

Newton’s second law

How does the acceleration obtained from the experiment compare with the value you found using Equation 6 (Use percentage error and chi-squared method to compare)

Report the acceleration obtained from your experiment along with its error.

Report the initial velocity of the glider obtained from your experiment along with its error.

Discuss the sources of uncertainty in your measurement.

 

What is the time constant of this circuit? How long will it take for the capacitor to reach 75% of its final charge? What is the final charge on the capacitor?

/in /by

Magnetic field and current related questions

An initially uncharged capacitor with a capacitance of C= 00 pF is connected in series with resistor with a resistance of R= 4.5 kn. If this series combination of circuit elements is attached to an ideal battery with an emf of f= 450 V by means of a switch S that is closed at time t = 0, then answer the following questions.

  • (a) What is the time constant of this circuit?
  • (b) How long will it take for the capacitor to reach 75% of its final charge?
  • (c) What is the final charge on the capacitor?

Chapter 20

A long, straight wire in the .r-y plane lies along the z-axis and carries a current of 3.5 A in the -kr An electron is also located in the r-y plane on the y-axis at y = —5.0 cm (r = 0). The electron is moving in the -ky direction (towards the long, straight wire) with a speed of 6.6 n 10° m/s.

  • (a) What is the magnitude and direction of the magnetic field vector due to the long, straight wire at the location of the electron?
  • (b) What is the magnitude and direction of the magnetic force on the electron?
  • (c) Include a diagram of the situation. [Diagram 3 pts.]

A square loop with 10 turns and a side length of 5.0 cm lies flat on a tabletop. The loop carries a current of 2.0 A that goes counterclockwise when viewed from above while looking down on the table.

(a) What is the magnitude and direction of the magnetic moment of the loop?

(b) If there is a uniform magnetic field with magnitude 0.75 Tat the location of the loop that heads down through the tabletop and makes an angle of 60° with the surface of the tabletop, then answer the following:

  • (i) what is the magnitude of the net magnetic force on the loop, and
  • (ii) what is the magnitude of the net torque on the loop?

(c) Include a diagram of the situation. [Diagram 3 pts.]

 

Based on your calculations, should EEC acquire the supplier? Why or why not? Which of the techniques (NPV, IRR, or payback period) is the most useful tool to use? Why? Which of the techniques (NPV, IRR, or payback period) is the least useful tool to use? Why?

/in /by

NPV, IRR, or payback period

Answer the following:

  • Based on your calculations, should EEC acquire the supplier? Why or why not?
  • Which of the techniques (NPV, IRR, or payback period) is the most useful tool to use? Why?
  • Which of the techniques (NPV, IRR, or payback period) is the least useful tool to use? Why?
  • Would your answer be the same if EEC’s cost of capital were 25%? Why or why not?
  • Would your answer be the same if EEC did not save $500,000 per year as anticipated?
  • What would be the least amount of savings that would make this investment attractive to EEC?
  • Given this scenario, what is the most EEC would be willing to pay for the supplier?

 

Develop an essay that consists of an evidence-based argument that supports your positions on how: aviation impacts climate change, and climate change impacts aviation.

/in /by

DOME: Aviation and Climate (PLG 1)

Develop an essay that consists of an evidence-based argument that supports your positions on how: aviation impacts climate change, and climate change impacts aviation.

Utilize mainly information and web-based sources included in the Module 9 Lesson to develop your essay. Supplement your discussion with other reliable sources as needed to support your argument. Include ALL sources used at the end of your essay and cite each source within the essay.

Discuss how aircraft can benefit from utilizing composite materials. In composites, the separate components do not disappear or else combine into a single entity with the whole.

/in /by

Respond to classmate discussion

Discussion post:

Researchers are working on a method to repair airplanes using composite patches, which can be affixed to both aluminum and the next generation of compound materials planes. The project’s objective is to minimize maintenance costs, improve aircraft reliability, and lengthen their service lives. Research is now being done with the goal of developing composite patches for use in aircraft repairs. These patches can be applied to planes made of aluminum as well as the next generation of compound materials planes. The objectives of the project are to cut down on the amount of money spent on aircraft maintenance while at the same time boosting aircraft reliability and improving aircraft service lives.

This article discusses how aircraft can benefit from utilizing composite materials. In composites, the separate components do not disappear or else combine into a single entity with the whole. When two or more different types of material are blended, the resulting product is referred to as a “hybrid,” and it has greater structural capabilities. However, repairs to composites are expensive, despite the fact that these materials are superior in terms of the aircraft’s ability to remain in service for a longer period of time. Because of this, manufacturers are looking into ways to help improve the composites’ reliability while simultaneously lowering the cost of repairs.

In my previous work, I was responsible for performing scheduled preventative maintenance on a variety of MDSs, including C130s, F16s, F15s, E3s, and HH60s. One of the most important “special inspections” that we had to perform was washing the aircraft, which included an inspection for corrosion as well as a cleaning of the aircraft. This was all required by corrosion control technical orders. One of the most important checks that are performed on these aircraft is called depot maintenance. During this check, the aircraft is taken to a hangar at the depot where it stays for anywhere from several months to an entire year. There have been situations when aircraft have needed to be repaired due to rust that was not discovered until after the aircraft had been disassembled at the depot. In these cases, the corrosion was discovered during the disassembly process. This can cause even more downtime for the aircraft in the hopes of repairing the aircraft for flight worthiness and longer the aircraft is gone longer the base has less aircraft to work with.

Figure 1

Carbon Composite Material Market

Picture1.5.png

Note. Use of composites: (a) Carbon Composite material market; (b) Materials used in a Boeing 787.

 

Discuss the degree of trust you have in the results based on the variability, uncertainty, and error in the testing. Also include an evaluation of the correctness of the hypotheses for each plane design, providing justification for the evaluation based on the testing.

/in /by

Paper Airplane Project Part 2

In part 2 of the project, during Modules 6 and 7, you will build and flight test models of each of your chosen glider designs.

Download and review the Paper Airplane Project Glider Design Testing Instructions (DOCX) Download Paper Airplane Project Glider Design Testing Instructions (DOCX)and Paper Airplane Project Glider Design Testing Worksheet (DOCX) Download Paper Airplane Project Glider Design Testing Worksheet (DOCX)documents.

Utilize the scientific method to build and flight test each of your glider designs, following the instructions outlined in the instructions document and completing the design and testing worksheet.

In the worksheet, for each design, state which test plane performed the best along with the average distance or time of that plane.

Then, summarize some results and conclusions based on the data and calculations from the testing of each design. Include some comparison of the flight characteristics of the best performing glider of each design to the other test gliders of the same design.

Discuss the degree of trust you have in the results based on the variability, uncertainty, and error in the testing. Also include an evaluation of the correctness of the hypotheses for each plane design, providing justification for the evaluation based on the testing.

 

When the switch changes the LED, write a comment on the LCD screen that says what the user should see in the LEDs.

/in /by

Mechanical Engineering

Combine tutorial 7 and 8. Tutorial 7 uses the relay as a switch between two LED options. When the switch changes the LED, write a comment on the LCD screen that says what the user should see in the LEDs. For example, say “Green LED on, Red LED off”. Basically, whatever is happening with the LEDs should be printed on the screen.

Post a summary of your glider design testing results to this discussion forum, and engage in a discussion with your instructor and classmates in both analyzing and comparing the results, and in reflecting on your learning experiences during the project.

/in /by

8 – Paper Airplane Project Part 3 – Wrap-Up Discussion

In Part 3 of the project, you will post a summary of your glider design testing results to this discussion forum, and engage in a discussion with your instructor and classmates in both analyzing and comparing the results, and in reflecting on your learning experiences during the project.

From the results submitted, the best-performing glider designs will be recognized as the most likely to succeed in the mock glider competition.

Create a summary of your design testing results, to include:

  • the name of each of the team’s chosen glider designs
  • a reference (URL) that contains an image of each glider and the instructions for building it a hypothesis for each design that incorporates predictions for how each of the four main forces that
  • act on aircraft will affect the motion of the glider in allowing it to achieve its objective (distance or duration)
  • a specific description for how thrust should be imparted to each glider design to maximize its desired performance (distance or duration)
  • the best average flight time achieved by a distance design test plane
  • the best average flight time achieved by a duration design test plane
  • a summary of the specific design features and external factors that likely influenced the performance of the test planes for each design

(Note: A-D were completed in Part 1 of the project; E-G will come from your glider design testing worksheet Results and Conclusions section)