Class 29: Monday, 12/1/22

Warm Up:    A spool car is wound up and released.  When the rubber band unwinds fully, a pin pops out, allowing the car to keep rolling.

1)  What forces are acting on the car while the rubber band is pushing it?

2)  What forces are acting on the car after the rubber band stops pushing, but before it stops rolling?

3)  If we wind the rubber band more, which of those forces will change?  How?

4)  How can we calculate those forces?

 

Today:

  • Check/Review Homework VIDEO
  • Announcement:  There will be two more quizzes before the unit test.  Quiz #2 is next class (Monday).
  • Spool Car Forces Lab PDF -- How do the forces acting on a spool car change when the car is wound more or less?
    • Example Problem -- packet p 14-15 VIDEO
    • Collect data together, the following groups of students (by last name) will share data
      • A-G (16 feet of winding) -- we will do this one first.  We may have to adjust the winding distances if this goes too far or not far enough.
      • L-P  (12 feet of winding)
      • R-W (8 feet of winding)
    • Perform calculations

Homework:   

  • Complete practice Quiz #2  PDF  .  Then check your answers.  You can find the answers and explanations in this video.
  • There will be a quiz (Quiz #2) on Monday, very similar in format to the practice quiz. 

 

Image result for car skidding to a stopClass 28: Tuesday, 11/29/22

Warm Up:    If you need to stop a car quickly, why should you avoid locking the tires and skidding?

Today:

  • Return slideshow grading sheets.  VIDEO.  If you want to correct and resubmit your slideshow for an improved grade, you can do that once.  Students who did not turn in the slideshow on time can turn it in, but you will not be allowed to submit corrections afterward.
  • Solve a "real life problem" with a sliding block of wood.  Do a practice together first on handout p.13.  VIDEO.  You can work on this alone or with a partner, but you need to be able to do this on your own.  It may be on the test.

Homework:   

Class 27: Friday, 11/18/22

Warm Up:    How can you create a nice scan of a drawing to insert in your slideshow?

Today:

  • Check/review the homework  VIDEO
  • Work on Water Rocket Slideshow, in Google Classroom.

Homework:   

  • None!
Class 26: Wednesday, 11/16/22

Warm Up:    Two identical triplets weigh 700N each.  They are both standing on properly-functioning bathroom scales in elevators (different elevators).  One bathroom scale reads 600N.  Another reads 700N.  The third reads 800N. 

1.  What does the reading on a bathroom scale always tell you?

2.  What is going on here?  Why do the scales have different readings?

Today:

  • Check/review the homework  VIDEO
  • Return and review Forces Quiz #1 VIDEO
  • Do some "standing on a bathroom scale in an elevator" problems (p. 12 of handout).  VIDEO
  • Work on Rocket Diagrams

Homework:   

Class 26: Monday, 11/14/22

Warm Up:    One way to find the center of mass (a.k.a. balance point) of a stick is to support it with two hands and then slowly move those two hands together until they meet under the stick's center of mass.  Why does this method work?

Today:

  • Students who were absent on Thursday, take the quiz.
  • Award the donuts.
  • Take some time to finish the homework (I'm not sure that I really made sure that people understood what the homework was, and that you had a copy).  VIDEO
  • The rocket analysis is postponed for now.  Instead, we're working on Friction.
  • Notes and Practice: Friction and the Normal Force -- pages 10-11 of the Unit 2 handout (PDF) Answers Last Year's video from class  Today's VIDEO
  • Disassemble rockets

Homework:   

Class 25: Thursday, 11/10/22

Warm Up:    According to Newton's 3rd Law, every force has an equal and opposite force.  So how do you win a game of tug-of-war?

Today:

  • Quiz
  • Final rocket launch
  • Disassemble rockets.  Remove duct tape, staples, weights, and string.  Recycle bottle plastic and large pieces of cardboard.  Return the weights to the peanut butter jar.  Stuff the parachute plastic in the bag (there will be a bag).

Homework:   

Class 24: Tuesday, 11/8/22

Warm Up:   

1. Which can you throw with more force, a Wiffle Ball® (0.045kg), a baseball (0.145kg), or a shot put (5.45kg)?  Or is there no difference?  Explain your thinking. Some calculations -- don't peek before thinking.

2. What limits the amount of force that you can apply when you throw an object?

Interesting Link:  article about the fastest pitch ever thrown

Today:

  • Check/review homework VIDEO
  • Practice quiz pdf  VIDEO
  • Work time -- next class is the last chance to fly your rocket.  Successful rockets (launch with proper parachute deployment) get +2% on the project.

Homework:   

  • Study for the quiz -- next class, similar to today's practice quiz
Class 23: Friday, 11/4/22

Warm Up:    This 50kg rower has an acceleration of -1m/s2.  She is pulling against the oars with a force of 100N. Draw and calculate all of the forces acting on the rower.

Today:

  • Check/review the homework VIDEO 
  • 10 minutes of rocket work time
  • Rocket launch -- send up a sensor in the rocket that has already proven to be successful

Homework:   

  • Complete #7 on Page 17 of the packet.  Answers
Class 22: Wednesday, 11/2/22

Warm Up:   

1.  How fast does chalk fall? Is it faster than a cat?... My spreadsheet answer

2.  Sometimes people celebrate special occasions by firing guns into the air.  Is this safe?

Image result for celebratory gunfire3. Why don't clouds fall out of the sky?

Calculated terminal velocities of various spheres.

Today:

Homework:   

  • Packet p. 18 -- parachuter "sudoku"  Answers
Image result for cat falling from buildingClass 21: Monday, 10/31/22

Warm Up:    According to this article, emergency clinic records of 132 cats that jumped from windows of buildings showed a 90% survival rate.  The average drop was 5.5 floors. 

Injuries increased with increasing heights up to 7 floors. When cats fell from over 7 floors, they actually suffered from “less injuries.”  Can you explain this surprising finding?

Today:

Homework:   

  • Packet P. 4
  • Packet p. 18 -- parachuter "sudoku"  Answers
Class 20: Thursday, 10/27/22

Warm Up:    I have a length of treated 4"x4" lumber, some large nails, a hammer, and a large rock.  How will it feel if I put the rock on my head and then have someone pound nails into the wood on top of the rock?

Today:

Homework:   

  • Finish answering the Newton Sled questions.
Class 19: Tuesday, 10/25/22

Warm Up:    Why can't you pick yourself up?

Today:

Homework:   

  • Complete #4 and #5 on page 17 of the handout.   Answers
Class 18: Friday, 10/21/22

Warm Up:    What will happen if I poke a knife through a potato, hold both objects in the air with the knife pointing downward, and then hammer the butt of the knife into the potato?  Why?  What if it's an apple, because I didn't have potatoes?

Today:

Homework:   

  • Complete the review questions on page 16 of the handout.   Answers
Class 17: Wednesday, 10/19/22

Warm Up:    None

Today:

  • Optional Test retake
  • If you have time, finish your parachutes (unless you've already done it) -- radii about 40cm and 15cm; 8 shroud lines

Homework:   

  • Due on Friday -- Finish the Practice Problems on pages 6 & 7 of the handout.   Answers
Class 16: Monday, 10/17/22

Warm Up:    It is possible to remove a sheet paper from under a dry erase pen without touching or tipping the pen.  How can one do this without tipping the pen?  Why does the pen usually fall? 

Today:

Homework:   

  • Test retake on Wednesday -- study (see videos in Google Classroom)
  • Due on Friday -- Finish the Practice Problems on pages 6 & 7 of the handout.   Answers
Class 15: Thursday, 10/13/22

Warm Up:    There is a heavy object suspended from the ceiling by a string.  Another segment of the same string is hanging downward from the object.  I am going to pull on the bottom string until one of the two strings breaks.  Which string is going to break first?  Why?

Today:

Homework:   

  • Study for test retake
Class 14: Tuesday, 10/11/22

Warm Up:   No warm-up today.  Star reader and then the test.

Today:

  • STAR Reader test
  • Short break -- last minute questions
  • Unit 1 Test -- Motion (Kinematics).  Take your time.  Check your work.  Don't skip questions.

Homework:   

  • No homework! 
Class 13: Wednesday, 10/5/22

Warm Up:   Go to this web page on your chromebook and open up the video segment where I am explaining how to do number 17 on the practice test.

Today:

  • Get a clean copy of the practice test (PDF) .
  • Check and review the homework. (Page 4, Page 5)
  • Begin the Water Rocket Project/Contest.
    • Today -- Make two parachutes.  The purpose of the small parachute is to deploy the large parachute. The purpose of the large parachute is to protect an altitude sensor that will help us create a graph of position (height) vs time. VIDEO showing a finished rocket. 
      • Watch this video --  Simple way to make a parachute.
      • Materials:  cardboard (for keeping under your hot glue gun), hot glue, string, scissors, plastic sheet (painter's drop cloth)
      • Parachute sizes:
        • Large parachute -- radius 40-50cm
        • Small parachute -- radius 15-20cm
    • Next week -- Make fins, a nose cone, and fuselage.  Try to build the rocket that will go the highest.  Any rocket that does not parachute safely to the ground will be disqualified.   After that, launch and collect sensor and video data.

Homework:   

  • Study for test next class -- Tuesday, after the STAR reader test -- sorry :-(
  • See lClass #12 homework for test studying suggestions.
Class 12: Monday, 10/3/22

Warm Up:   How should you study for Tuesday's test?

Today:

Homework:   

  • Finish the practice test.
  • Study for Tuesday's test.  Practice the problems and questions on the practice test.  Use a clean copy to test yourself.  Do not simply memorize answers, because most of the answers will change.  Make sure that you unerstand the concepts. If you don't understand something, watch the video (links above).  Talk yourself through how the test might be different, and how that would affect your work.  Practice, ahead of time, until you know everything.  Then practice again on Monday night.
Class 11: Thursday, 9/29/22

Warm Up:   Consider the case of this ball.  At t = 0s, the ball is flying directly upward with a speed of 20m/s.  Sketch graphs of the ball's position, velocity, and acceleration (vs. time) over the next 4 seconds. 

Let's assume that there is no air resistance and that g = 10m/s2.

 

Today:

  • Return the Spool Car Analyses and discuss the grading.  Fix it and re-submit if you want to improve your grade. 
  • Check/review homework VIDEO
  • The last bit of notes (and practice) with kinematics formulas -- p. 13 and 14.  VIDEO
  • Work time  -- start on your homework
  • Unit 1 Packet (PDF).  Answer Key

Homework:   

  • Packet p. 19 -- The end! (of the packet)
Class 10: Tuesday, 9/27/22

Warm Up:   A unit conversion problem...

1.  How old is someone who has lived a billion seconds?  Have you lived that long?

2.  What is the significance of 1 billion heartbeats?

 

Today:

  • Can you guess the lowest grade in the class, right now?  What do you think it will be after our first test?
  • Check/review homework VIDEO
  • Notes and practice with unit conversions, on p. 14 of the packet  VIDEO
  • Finish Spool Car Analysis Activity See Assignment in Google Classroom.  Here's my example.
  • Work time  -- start on your homework
  • Unit 1 Packet (PDF).  Answer Key

Homework:   

  • Complete questions from two pages in the packet:
    • page 15, #9-11
    • page 18 -- whole thing.  This is the 3rd page of the test review.
    • Here's the Answer Key 
Class 9: Friday, 9/23/22

Warm Up:   If you throw a ball straight up with a velocity of 10mph...

1.  What's its velocity at the highest point?

2.  What's its velocity just before it returns to your hand?

Today:

  • Check/review homework VIDEO
  • Notes -- Free-fall on p. 8  VIDEO
  • Spool Car Analysis Activity (**Instructions for today VIDEO**):  See Assignment in Google Classroom.  The directions in the google doc have changed.
  • Work time  -- start on your homework

Homework:   

  • Complete page 17 in the packet. Answer Key  This is the 2nd page of the test review.
Class 8: Wednesday, 9/21/22

Warm Up:   The world record rubber band car traveled this 5m distance in 2.82 seconds.  What was its average velocity?

Today:

  • Check/review homework VIDEO
  • Spool Car Analysis Activity (Instructions for today VIDEO):  See Assignment in Google Classroom
  • Work time  -- start on your homework

Homework:   

  • Complete p.16 in the packet. Answer Key  This is the first page of the test review.
Class 7: Monday, 9/19/22

Warm Up:   Velocity and Acceleration Combinations Matching Quiz.  Use this link to take the quiz, or take it in Google Classroom.

Today:

  • Check/review homework VIDEO
  • Spool Car Analysis Activity:
    • In groups of no more than 3, assemble a spool car.  Again, here's how to assemble them...VIDEO
    • Practice and/or reconfigure the car to make it go as fast as possible over the 5 meter long course.
    • Get a video made of your car traveling from one blue tape to the other -- Mr.Stapleton will do it.
  • Work time  -- start on your homework

Homework:   

  • Complete #8-12 on p. 10 and 11.  Use each graph to calculate acceleration.  Solutions
  • Videos from last year's class showing how to do these...
Class 6: Thursday, 9/15/22

Warm Up:   What is a spool car?  How does one work?

Today:

Homework:   

  • Complete #1,2,3, and 7, on p. 10 and 11.  Use each graph to calculate acceleration.  Solutions
Class 5: Tuesday, 9/13/22

Warm Up:   Suppose a pendulum is allowed to swing back and forth from left to right (and back).  At what points in the pendulum's motion does it have these combinations of velocitya and acceleration?

Today:

  • Check/review homework -- practice some position graphs
  • Finish the "Creating Velocity and Acceleration Combinations" assignment in Google Classroom.
  • Spool Car preview

Homework:  Complete the position graphs on p.8-9 of the Unit 1 Packet (PDF).  Answer Key

Class 4: Friday, 9/9/22

Warm Up:   Suppose you want to record the motion of a cart (1) moving on a track (2), using a motion detector (3).  Your goal is to produce a graph with positive velocity and zero acceleration.  You can use few books (4) and a computer (5) to do this.  How can you do this?

Today:

  • Check/review homework (#2 velocity graph on page 8)
  • Acceleration Notes -- P.6-7 of the packet (Answer Key) VIDEO from class today
  • Graphing and matching motions, and creating motion graphs and describing their motion (p.8-9) -- try the examples and 1-4 together, using the motion sensor, on the TV?  Then do 5-8 on your own.
  • Activity -- Complete the "Creating Velocity and Acceleration Combinations" assignment in Google Classroom.

Homework:  Complete the acceleration graphs on p.8-9 of the Unit 1 Packet (PDF).  Answer Key

Class 3: Wednesday, 9/7/22

Warm Up:   1) Suppose you want to walk in front of a motion sensor and produce the velocity graph shown here.  How do you do it?

2) What would a graph of your position vs. time look like?

Today:

Homework:  Complete #2 on page 8 of the Unit 1 Packet (PDF).  Just draw the velocity graph.  Here's the video from class showing how we did this with a graph on page 7.

Class 2: Friday, 9/2/22

Warm Up:  

The graph on the right shows the positions at different times for seven different people, relative to a motion detector at the 0m mark.  Which person (people) was (were)...
  1. moving at a constant speed
  2. moving toward the sensor
  3. not moving at all
  4. accelerating
  5. decelerating
  6. accelerating the fastest
  7. moving at the fastest constant speed

 

Today:

  • Check for completion of packet p1.
  • Discuss Motion Matching Answers (p.1). VIDEO
  • Some practice quizzing over position graphs.  What do they mean, and how are they different?  VIDEO
  • Notes -- Introduction to Kinematics, p. 2-4 of the Unit 1 Packet (PDF) Unit 1 Packet Answer Key VIDEO
  • Homework time

Homework:  

  • Complete #5-8 on page 4 of the Kinematics Intro notes, if you didn't finish it during class
  • We will have a short practice quiz next class over position graphs (similar to page 1 of the packet, and the motion matching activity).  It won't count toward your grade, but you may want to review page 1 of your notes beforehand.

 

Class 1: Wednesdsay, 8/31/22

Warm Up:  

Spin one of the "sprotating cylinders" by pressing one end until it squirts out from under your finger.  Try pressing the other end.

When the cylinder is spinning, why do you only see the symbol that you press?

 

Slow motion

Today:

Homework:  If you didn't finish the motion matching questions (Unit 1 Packet, page 1), finish them before next class.  Answer Key