In this mirror lab, we got to visualize how light travels through and bends from mirrors and lenses. I enjoyed completing this lab because it was very cool to see how the light traveled through the mediums. If I were to do this lab again, I would convert my measurements to meters as soon as I collected the measurements so that I could make sure that I had the correct data. Also, I would analyze the pictures provided more closely so that I can take all of

my measurements correctly.

Facts about the gases that are present in our atmosphere:

• 78.08% Nitrogen and 20.95% Oxygen
• element size = small
• they scatter VIOLET and BLUE light
  • this is why we see the sky as a blue color
  • the violet color isn’t as prevalent to our eyes

Considering this, we can also infer that this information supports the idea that:

• Earth is perceived to have a blue glow around it when observed from space

 

This information is essential in the application of color in our everyday lives because it is supported by the Tyndall Effect, a concept that is very important in color. Below is a visual description of this concept:

 

• Reflection:
  • Memorization is key when learning how to masterfully evaluate color practice problems. I chose to solve many visual practice problems this week because I am not a very visual learner and I have intentions of changing this. By solving these problems, I not only just helped progress my memorization of the color combinations, but I also helped myself visualize the circumstances under which these problems occur.

• In physics, the one piece of knowledge that is essential for us to know is that painting and physics colors aren’t the same and don’t yield the same results when mixed. Below is a short summary of their differences and pictures of the notes that I used to grasp this tricky concept.
  • Physics Colors:
    • yellow, cyan, and magenta
    • when mixed –> true black color
  • Painting Colors:
    • red, blue, and yellow
    • when mixed –> brown color

• I decided to include my color notes in my learning log because of the importance of the difference between primary and secondary colors in color addition and in color subtraction.
  • Addition:
    • primary = red, blue, and green
    • secondary = magenta, cyan, and yellow
  • Subtraction:
    • primary = yellow, cyan, and magenta
    • secondary = red, green, and blue
• This subtle difference is very important in the viewing of color because different colors yield different absorption and reflection colors when certain colors are shone on an object and with or without different filters.

• I decided to include these notes in my learning log because, in order to fully grasp the concepts of resonators, standing waves, and harmonics, you must be familiar with the different types of resonators what they look like. I had a very hard time understanding this topic because all of the resonators looked very similar and displayed very subtle differences that set them apart.

• Reflection:
  • The completion of these practice problems helped me feel confident in my ability to solve all types of power problems. Because I did a series of problems that may have seemed a bit repetitive at the time, the practice method helped me “drill” the formulas into my head. By the end, I started to enjoy evaluating the problems because of how simple they became for me. However, I was very confused by my last practice problem so I was unable to complete it.

• Reflection:
  • I decided to complete some additional dimensional analysis problems because it is a mathematical method that is used in most physics calculations. By the end of my practice, I felt as if I had mastered the concept of dimensional analysis because the problems became much easier for me to visualize and evaluate. As a result of my mastery, I gave myself some more complicated problems at times so that I could test and challenge my advanced knowledge.

• Reflection:
  • These practice problems greatly benefited my personal knowledge of forces because I addressed problems for all of the aspects of forces. Although I found these problems pretty simple, I did have trouble drawing out FBDs for the problems that required them because I am not a very visual learner.

Purpose:  To determine the amount of power generated when walking and running up the stairs.

Caution:  ONLY RUN AS QUICKLY AS YOUR ARE WILLING TO GO SAFELY!

1.  Your weight in pounds: 130 lbs Your weight in Newtons: 580 N

(Show your work below, look up the conversion factor)

59 kg x 9.8 m/s^2 = 578.2 N → 580 N

2.  Height of flight of stairs: 2.14 m
3.  Work required for YOU to run up the stairs: 1200 J

(Show your work below)

580 N x 2.14 m = 1241.2 → 1200 J

4.  Work required for YOU to walk up the stairs: 1200 J

(Show your work below)

580 N x 2.14 m = 1241.2 → 1200 J

5.  Average Time required to run up stairs: 2.7 seconds

• Show Collected Data:

Time

3.10 s

2.52 s

2.50 s

 

6.  Average Time required to walk up the stairs: 5.6 seconds

• Show Collected Data:

Time

6.30 s

5.36 s

5.13 s

 

7.  Power generated while running up stairs: 460 Watts

(show work below)

Power = work/time =        force x displacementtime= 580 N x 2.14 m2.7 sec= 459.70 Watts → 460 Watts

8.  Power generated while walking up stairs: 220 Watts

(Show your work below)

Power = work/time  = force x displacementtime= 580 N x 2.14 m5.6 sec= 221.64 Watts → 220 Watts

9.  Convert Power in watts to horsepower for running: 0.62 HP

(show work!)

460 Watts1x 1 HP746 Watts= 0.6166 HP → 0.62 HP

12.  Convert Power in watts to horsepower for walking: 0.29 HP

(show work!)

220 Watts1x 1 HP746 Watts= 0.2949 HP → 0.29 HP

Discussion Questions:

1. Discuss the precision and accuracy of your data, and what you could do to increase the precision of your data.

• High Precision because each of my trial times are within 0.10 seconds of each other
• Accuracy is not important in this lab because there is no set time that we can compare our data to. This data collection is based on personal ability and can’t be compared to a set time
• To increase the precision of my data, I could take the same amount of time to rest before each trial, skip the same amount of steps each time, and complete each trial with the same physical and body conditions

 

2. How did the work and power compare between walking and running up the stairs?

• The work for running and walking up the stairs was the same because the time is not factored in to the work equation. Also, my mass and the height of the stairs was the same when I ran and when I walked up the stairs
• The power for running and walking was different for running and walking because it takes more energy to go up the stairs at a faster rate than it does to leisurely walk up the stairs at a slow pace.

– % change of running to walking power = Running – WalkingRunningx 100 = 460 Watts – 220 Watts 460 Watts x 100 = 52.1739 % → 52%

• Running Power was 52% more than Walking Power

3. What could you do to increase your power while running?

• To increase my power while running, I could increase the time it takes me to run the same distance up the stairs.

 

4. Look up the car you drive and find how much horsepower it produces. How does your power compare, and just based on the horsepower, how quickly would it be able to go up the same stairs if using just your mass (this is to pretend that you had the horsepower of your car)?

• My 2016 Hyundai Tucson produces 164 HP
• My power is 0.29 HP
• Power = work/time =        force x displacementtime→ 580 N x 2.14 m?=164 HP

→  580 N x 2.14 m = 164t HP → 580 N x 2.14 m164= 7.6 seconds