Centroids Power Point

Centroids worksheet

Solutions to #1 & #2

Solutions to #3 & 4

Gears and Gear Ratios

Answers to the Gears extra practice

Power point slide for gears

Notes for gears project

Gears Project

Rotational equilibrium lab

Mechanical Advantage Worksheets

1. Levers
2. Wheel and Axle
3. Pulley
4. Inclined Plane

http://phet.colorado.edu/sims/html/balancing-act/latest/balancing-act_en.html

Rotational equilibrium lab

Can Crusher Lab Activity

Due Wednesday October, 16 2018

Link to the can crusher lab

Power point requirements ( 10 points) group grade

• Introduction slide, all creators, logo, appropriate title for the can crusher
• Each person's initial design should be displayed
  • Everyone should take some time and discuss their initial ideas, inspiration for that idea, and pros/cons to that idea.
• Include your decision matrix to help us see how you chose your final design and discuss why. (2 points)
• Include your blue print for the final design and it should be specific. (2 points)
• Show the can crusher working (3 points)
  • Discuss the strengths and weaknesses to your design, how efficiently does it work or does it get snagged a lot?
• End the presentation by discussing what are the strengths and weaknesses to your design. (2 points)
• Everyone in the group must contribute similar parts (1 point)

September 17-21

• Monday- Took SLO science interpretation test and practiced unit conversions
• Tuesday-Introduce Mechanical Advantage
  • Link to power point
• Wednesday-Continue Mechanical Advantage
• Thursday- Unit Conversion Quiz

September 10-14

• Monday- How to send a proper email & characteristics of a good email. Wrap up drawing and design process
• Tuesday- introduce the PLTW website, administer passwords
• Wednesday- Introduce engineering notesbooks

Bridges Units

Computer numbers and groups

Week 1- Design process of the bridge (March 4-9th)

• This week you will be using your prior knowledge about forces and distance to try to understand how the concept of stress on a truss can effect the overall stability of a bridge.
  • Key Vocabulary
    • Compression - A force arising from a beam being pushed together from outside forces
    • Tension - A force that is pulling a beam apart
    • Slenderness- The ratio of length to radius of gyration (think of it similar to the length/ (mass distribution around the radius)
    • Truss- A beam of a bridge
    • Stability- a measure of how secure the object is

Part one of the project involved you designing a bridge on the West Point Bridge Builder (due at the start of class Wednesday)

1. You need to design a bridge that has a total cost less than $550,000
   1. You will lose 1 points for every $50,000 over
2. Your bridge should not have any force/stress ratios that are greater than 0.3
   1. You will lose 0.5 points for every one truss that has a compression or tension force greater than 0.3
   2. Compression is red and represents pressure pushing a truss inward from the forces of gravity
   3. Tension is represented with blue and represents a truss being pulled apart

Part two- As a group pick the person with the best design (cheapest and most sturdy) and transcribe the measurements of your bridge. (Due at the start of class Friday)

1. You will need to convert the lengths from the simulator onto a physical length for your scale model.
2. The gap of your bridge is 36 meters on the simulator which will correlate to a gap of 46.5 centimeter gap for the bridge tester.
   1. To scale your model multiply all of your lengths in the simulator by 1.29 cm/m
   2. On a large piece of paper (provided by Mr. Goeldi) draw the scale model of your bridge.
      1. Show your conversions for each truss to Mr. Goeldi before you start designing your bridge.
      2. You will also need to have beams running across both parts of the bridge to hold it all together
      3. Beams that are "solid" beams in the simulation will be allowed to use two balsa wood pieces glued together
   3. Color code your blue print
      1. High compression trusses will be colored red
      2. High Tension trusses will be colored blue
         1. The colors will be addressed in your video in part 4
   4. You will need to calculate how many total strands of Balsa wood you will need before you begin construction.
   5. Based on your total length, calculate the total cost of your bridge. Each full length stick of balsa wood costs $10,000

Week 2- Building the bridge (March 11-15)

Part 3- Build your bridge (Due at the end of class Wednesday)

1. Based on your blue print, cut all your trusses out of balsa wood and glue your bridge together.
2. By the end of the day on Wednesday your group needs to have tested your bridge on the Bridge Tester and your maximum force gathered.

Part 4- Youtube video illustrating your bridge.

This needs to be completed by the time you leave for spring break.

1. Show off your bridge, discussion features like
   1. Total amount of Balsa Wood
   2. Total cost of the bridge
   3. Where do you predict it will collapse
   4. How confident are you in your bridge and why
2. Record the bridge being tested in slow motion. In your video only show the part of the bridge that relates to the bridge collapsing.
3. Referencing your blue print in the video
   1. Discuss how did the bridge do compared to what you predicted
   2. Did the beams you predicted to have compression or tension demonstrate compression or tension?
   3. What will you do next time?
   4. Total cost of bridge ($10,000 per balsa stick)/ maximum force held
   5. 
      

Part 5- Peer Evaluation - Due before you leave for spring break. If you do not do this you will lose the 5 points from the peer evaluation.

Bridge Simulator using west point bridge builder

Bridges Units

Computer numbers and groups

Week 1- Design process of the bridge (March 4-9th)

• This week you will be using your prior knowledge about forces and distance to try to understand how the concept of stress on a truss can effect the overall stability of a bridge.
  • Key Vocabulary
    • Compression - A force arising from a beam being pushed together from outside forces
    • Tension - A force that is pulling a beam apart
    • Slenderness- The ratio of length to radius of gyration (think of it similar to the length/ (mass distribution around the radius)
    • Truss- A beam of a bridge
    • Stability- a measure of how secure the object is

Part one of the project involved you designing a bridge on the West Point Bridge Builder (due at the start of class Wednesday)

1. You need to design a bridge that has a total cost less than $550,000
   1. You will lose 1 points for every $50,000 over
2. Your bridge should not have any force/stress ratios that are greater than 0.3
   1. You will lose 0.5 points for every one truss that has a compression or tension force greater than 0.3
   2. Compression is red and represents pressure pushing a truss inward from the forces of gravity
   3. Tension is represented with blue and represents a truss being pulled apart

Part two- As a group pick the person with the best design (cheapest and most sturdy) and transcribe the measurements of your bridge. (Due at the start of class Friday)

1. You will need to convert the lengths from the simulator onto a physical length for your scale model.
2. The gap of your bridge is 36 meters on the simulator which will correlate to a gap of 46.5 centimeter gap for the bridge tester.
   1. To scale your model multiply all of your lengths in the simulator by 1.29 cm/m
   2. On a large piece of paper (provided by Mr. Goeldi) draw the scale model of your bridge.
      1. Show your conversions for each truss to Mr. Goeldi before you start designing your bridge.
      2. You will also need to have beams running across both parts of the bridge to hold it all together
      3. Beams that are "solid" beams in the simulation will be allowed to use two balsa wood pieces glued together
   3. Color code your blue print
      1. High compression trusses will be colored red
      2. High Tension trusses will be colored blue
         1. The colors will be addressed in your video in part 4
   4. You will need to calculate how many total strands of Balsa wood you will need before you begin construction.
   5. Based on your total length, calculate the total cost of your bridge. Each full length stick of balsa wood costs $10,000

Week 2- Building the bridge (March 11-15)

Part 3- Build your bridge (Due at the end of class Wednesday)

1. Based on your blue print, cut all your trusses out of balsa wood and glue your bridge together.
2. By the end of the day on Wednesday your group needs to have tested your bridge on the Bridge Tester and your maximum force gathered.

Part 4- Youtube video illustrating your bridge.

This needs to be completed by the time you leave for spring break.

1. Show off your bridge, discussion features like
   1. Total amount of Balsa Wood
   2. Total cost of the bridge
   3. Where do you predict it will collapse
   4. How confident are you in your bridge and why
2. Record the bridge being tested in slow motion. In your video only show the part of the bridge that relates to the bridge collapsing.
3. Referencing your blue print in the video
   1. Discuss how did the bridge do compared to what you predicted
   2. Did the beams you predicted to have compression or tension demonstrate compression or tension?
   3. What will you do next time?
   4. Total cost of bridge ($10,000 per balsa stick)/ maximum force held
   5. 
      

Part 5- Peer Evaluation - Due before you leave for spring break. If you do not do this you will lose the 5 points from the peer evaluation.

Bridge Simulator using west point bridge builder