Physics Lab Experiment Ohms Law Finding Resistance Lab Report

Lab 2

Name__________________________________________ Due date: October 5 

1. I. The objectives of this lab are(1) to determine the resistance of a cylindrical resistor experimentally (2) to compare the experimental ( E ) value of resistance with the actual (A) value of resistance.
2. Apparatus(Equipment): Voltage source, ammeter that measures current , voltmeter that measures voltage.

III. Procedure:  The currents (I) flowing through a resistor were measured by applying different amounts of voltages (V) to a resistor.

1. IV. Raw Data: The voltages applied, and the corresponding currents  are indicated in the raw data table below

1. V. DATA ANALYSIS: (1)Using Ohm’s Law and showing your steps , calculate the value of resistance R or each row in the above table. You need to convert milliampere to  Ampere while using Ohm’s law .  Note that 1 ampere = 1000 milliampere. You will get a total of five  values of R. (2) Determine the average of the five values of R. The average value of R will be the Experimental Value of the resistance. Usually it is denoted by the letter E (E is used to indicate that it is an experimental value). The Actual value of resistance is indicated by   the letter  A .

The actual value of the resistance of the resistor determined by the manufacturer is  A = 30 Ohms   

 Percent error =  X 100 %  =  

(3) Calculate the percent error by  using the value you obtained for the experimental resistance (E ) and the actual resistance A = 30  Ohms   

1. VI. QUESTIONS:
2. If the length L and area A of the resistor were measured, is it possible to identify the type of material within the resistor? Explain.

2. The variables in Ohm’s Law are V, R and I. The variables in Newton’s second Law are F_net, M and a. Explain that Ohm’s Law is similar to Newton’s second law by indicating the similarity of the variables in the two laws. For each variable in Ohm’s law , find the corresponding variable in Newton’s second law and explain why they are similar.

3. Using the first row data, calculate the number of electrons that flow in the resistor in one second. Explain.

4. Suppose the experiment was repeated by applying the same voltages using another (new) cylindrical resistor made from the same material used for the resistor in the experiment. If the new resistor has the same length (L) but twice the area as the one used in the experiment, will the currents stay the same, double or halve? Why?

VII. Sources of Error: What are the possible sources of error for this experiment?

VIII. Conclusions: Write down your conclusions. In your conclusions describe if you achieved your objectives and what you have learnt from the experiment.

PHYSICS LAB REPORT Measuring the Acceleration due to Gravity

• Virtual Laboratory part:

https://phet.colorado.edu/sims/html/projectile-motion/latest/projectile-motion_en.html

Measuring the Acceleration due to Gravity (g)

Objectives:

In this experiment you are going to study the nature of free fall motion by observing the position versus time, then to determine the acceleration of gravity (g)

Theory:

The acceleration that you are going to determine in this experiment is known as the acceleration of free fall, or the acceleration due to gravity. Its value is often taken as 9.81 m/s²  and given the special gravity acceleration symbol (g).

If an object is dropped from a certain height (y) and falls for a time (t), then its equation of motion can be written as:

Where V_o is the initial velocity which is equal to zero if the object falls from rest, and the previous equation can be rewritten as:

To verify the objective of this part using phet interactive simulation, do the following:

• Open the following link:

https://phet.colorado.edu/sims/html/projectile-motion/latest/projectile-motion_en.html

• From the home page of this link, click on lab, from lab window use the provided controllers to adjust the height (y) and the velocity of the lunched ball, the mass, the objects shape (see the Figure ). Adjust the first height at 14m and the velocity must be at zero (Free Fall). Release the ball and use the time meter (control the time meter and fix it at the final point of the ball) to measure the time needed for the ball to travel 14m in vertical direction. Record your data in table 1.
• Change the height (y) to 13m, release the ball and measure the time needed to travel 13m in the vertical direction. Record the new values in table 1.
• Repeat step 3 to fill table 1

Data Analysis:

• Complete table 1, Calculate ½ t².
• Use Excel software to plot the relationship between ½ t² and y.
• From the graph find the acceleration of gravity (g) which is equal to the slope.

Table 1

Slope =       ?

g _exp =        ?                                                                                

Questions:

• What is a free fall?
• When we say g = 9.81 m/s², what does this mean?
• An object is thrown up from the surface of earth, determine the direction of the acceleration in the following cases:

1. The object is going upward.
2. The object at its maximum height.
3. The object is going downward.

• Convert the value of g from m/s² to cm/s²
• Based on your knowledge, why the gravitational acceleration of the earth is much greater than the gravitational acceleration of the moon

Extend your knowledge:

• Try to drop a paper and a ball from the same height and answer the following questions:

1. What are the forces acting on the ball and the paper?
2. Which object reached the floor faster?
3. Do both objects fall with the same speed? Why? (Elaborate your answer)

• Problem-Solving part:

Problem 1:

You throw a rock up into the air as hard as you can, and it went back again to your hand. It stays in the air a total of 6.0 s.

1. Draw a diagram for the rock as it moves, identifying the positive direction of motion.
2. Identify the velocity of the rock at its maximum height.
3. What was the velocity of the rock when you threw it?

Problem 2:

A train moving on a straight track accelerates from rest at 2 m/s² for 20s. It then moves at constant speed for 2 min. It then decelerates uniformly to a stop in 10s.

1. Identify the type of motion of the train for the first 20s.
2. Find the displacement of the train for the first 20 s.
3. Identify the type of motion of the train for the next 2 min.
4. Find the displacement of the train for the next 2 min.
5. Identify the type of motion of the train for the last 10 s.
6. Find the displacement of the train for the last 10 s.
7. Find the net displacement (Δ x) of the train.

1. Prepare an outline of a reliability policy for your organisation showing the main headings and a 1 paragraph scope for each heading. If you use an existing policy, you are to comment on the strengths and weaknesses of the policy. Show how the reliability policy would link to other documents such as quality, production and maintenance policies and reliability manual.
2. Consider the reliability issues for elements such as water (surface and subsurface), seeds, natural fibres, energy, and food sources of all kinds. Discuss how a reliability policy could be relevant for their sustainable governance.
3. Conduct a literature review of current (under 5 years since publication) digital and hardcopy sources on reliability references from the library or other professionally reliable sources. Select 5 references and include a one-sentence comment why the reference is relevant to you.

However, for assignment purposes the simplified A4 landscape format as follows is acceptable. Item 1 should be the reference that you consider to be most important.

 
Prescribed and Recommended Textbooks
Title: Reliability Toolkit: Commercial Practices Edition
Author: Reliability Analysis Center
Publisher: RAC, Rome NY
Title: Practical Reliability Engineering
Author: O’Connor PDT
Publisher: Wiley
Edition/Year: 5th
Title: Reliability, Maintainability & Risk
Author: Smith DJ
Publisher: Butterworth-Heinemann
Edition/Year: 7th or 8th edition
As a reliability engineer, you should sift through the wide range of reliability requirements from different sources, and tailor the requirements you select to an understandable, logical, useful, and cost-effective asset management and reliability strategy. You are also encouraged to use other relevant texts, including those on line. Where assignment work includes company specific information, I will treat all such information as “company confidential”. It is important to be able to formally communicate your ideas through reports of various types, graphs etc.

Objective: To demonstrate application of the concepts of process hazard recognition and control learned over the course of this semester
 
Task: Conduct a hazard analysis exercise for a product manufacturing step within Biopharma, Semiconductor, Food and Beverage, or Oil and Gas Industry
 
Deliverable: Power Point (or equivalent) Presentation with a Short Video Explanation
5 Slides

• Slide 1 – Overview of the process being examined. What is it and how is it done?
• Slide 2 – Process steps – What are the main process steps? What chemicals/materials/equipment are used?
• Slide 3 – Using one of the hazard identification processes we learned in class, outline the main hazards associated with this process.
• Slide 4 – For each hazard identified, what are the consequences of that hazard? For example, if a thermal hazard exists, there may be possibility for skin burns, heat exhaustion, or even fire or runaway chemical reaction.
• Slide 5 – What controls would you recommend for each of your identified hazards?

You can either record a power point with voice-over, or simply include a YouTube video of your explanation of your slides, recording yourself as if you were presenting this live.  If you need help with either of these options, let me know.  I will also post some resources to help all of you with this.
 
Have fun with this! Choose something you are interested in learning more about. There are many resources available online about how things are made, including great videos and articles.