The Curriculum of the Steiner School - Class 7

Notes and Lesson Plans

Physics: Mechanics
updated June 20, 2021

Recorded here is my own personal collection of articles, resources, favorite links, teaching ideas, and lesson plans. It encompasses many years, from the very beginning of my experience studying and learning about Waldorf to the present time. People from all around the world visit my site and recommend it to others. Welcome!

This site records my journey. I hope my honesty is encouraging and helps break down some barriers that may prevent people from trying Waldorf methods. Because this is an ongoing site documenting my curriculum planning and ideas, some materials are more Waldorf-y than others. Please feel free to take what you like and leave the rest.

Physics: Mechanics (PDF)
for Class 7

Mission Statement - Consulting Services - Lending Library

Physics is Fun!
A Sourcebook for Teachers

by Rudolf Trostli
This is the best and only book you need for Middle School Physics.

Mechanics, i.e. Simple Machines
With my oldest daughter I had to rush through Mechanics as a part of a larger speedy Physics overview. With my youngest daughter I had the time to devote an entire block (four weeks) to Mechanics. We did this as a mixed age (7 to 13) main lesson block to kick off the homeschool year.

Week One

Week Two

    Day Five - Momentum

    Newton's Third Law leads us to normal force...

    finish adding forces to MLB, if needed

    review forces - Three Hole Bottle Inquiry Experiment - normal force, air pressure due to gravity, water pressure due to gravity

      2 liter plastic water bottle with three evenly-sized holes drilled into it, duct tape, water, sink

    and the Balloon Car STEM Challenge: Engineering Design Process... which actually I ended up moving to week three for Wheel & Axle!

    Balloon racers rely on Newton's Third Law of Motion. As the air rushes backward out of the balloon it pushes the car forward in the opposite direction with an equal force.

    (This is optional because you may already feel like this is covered with the Hovercraft... although I felt like the hovercraft was a bit of a bust because the kids expected it to move more rapidly and to be higher off of the table and so did I. I actually thought that just blowing up a balloon nice and big and letting go and watching it zip around the classroom was a fine demonstration of Newton's Third Law.)

    and it also leads us into playing with a Newton's cradle (if you want a really nice one for your classroom, or to give as a Christmas present, check this out!)

    Time to move on to Momentum.

    Momentum can be defined as "mass in motion."
    p = mv

    Impulse and its related formulas
    For 8th graders, do the Quick Quiz!

    go over real life examples of "big t, little F" and "little t, big F"

    egg and bed sheet, egg toss real life applications
    remind students that fire fighters used to use a bedsheet to catch people when they jumped from windows

    ending with an egg toss (big t = little F) was perfect!

    Day Six - Kinetic and Potential Energy

    add Newton's Second and Third Laws, the formula for Momentum, and the formula for Impulse and Change in Momentum (big t = little F) to MLBs

    Egg Drop Interactive online... then plan how you would build your own Egg Drop contraption (give this some thought for HW)

    learn about potential energy and kinetic energy, revisit Newton's cradle

    stretched rubber bands are loaded with potential energy - offer Rubber Band Snap Art as a work choice

    *NEW* Ramp Lab (this is a pretty simple middle school version -- she also has a high school version. "In this lab students build ramps with textbooks and meter sticks. They will change the height of the ramp and the mass of the balls rolling down and measure how it affects the amount of potential energy. Students will use the formula PE=mgh and find the relationship between potential energy, height, and mass.")

    introduce pendulum with Galileo biography, if you haven't already read it
    (short biographies of Galileo and Newton are found in Mathematicians are People, Too: Stories from the Lives of Great Mathematicians, volume 1)

    Day Seven - Egg Drop Activity

    an egg off the ground is also a perfect example of potential energy

    EGG DROP CHALLENGE -- this takes a lot of time but is totally worth it
    free PDF of egg drop challenge design sheet
    free PDF of prediction/results sheet

    Note: A few more options for Potential and Kinetic Energy are Peg's Paddleboat ($9.00) and Rubberband Racer ($15.00), both powered by a rubber band, and the Trimaran ($25.00), powered by a balloon, all from Nova Natural.

    Day Eight - Pendulum Experiments

    Energy in a Pendulum
    "At its highest point (Point A) the pendulum is momentarily motionless. All of the energy in the pendulum is gravitational potential energy and there is no kinetic energy. At the lowest point (Point D) the pendulum has its greatest speed. All of the energy in the pendulum is kinetic energy and there is no gravitational potential energy."

    pendulum experiments -- this also takes a lot of time but all you need is a pencil and some tape to tape the pencil to the top of your chalkboard, a long piece of string, an S-hook, a bunch of washers, a piece of chalk, and a stopwatch

    (Actually, I sent home Pendulum Packages with kids who wanted the supplies to experiment some more. I just used Talenti containers -- which won't break in a backpack -- and put in a long piece of hemp twine, an S-hook, and a bunch of assorted washers. The kids were delighted!)

    add Potential and Kinetic Energy to MLB

    we ran out of time but I would have loved to do

Week Three - Work and Simple Machines
(I have revised my pacing on this, based on experience. The last three simple machines are quick, are variations of one another, and can easily be done in the same day.)

    Day Nine - Lever

    Work = Mass x Gravity x Height
    Work = Force x Distance

    remember how big t = little F... this is also true when a machine helps with work... big distance = little F

    Work is done upon an object whenever a force acts upon it to cause it to be displaced.
    "Work involves a force acting upon an object to cause a displacement.
    In all instances in which work is done, there is an object that supplies the force in order to do the work."

    "When the work is done upon the object, that object gains energy. The energy acquired by the objects upon which work is done is known as mechanical energy. Mechanical energy is the energy that is possessed by an object due to its motion or due to its position. Mechanical energy can be either kinetic energy (energy of motion) or potential energy (stored energy of position). Objects have mechanical energy if they are in motion and/or if they are at some position relative to a zero potential energy position (for example, a brick held at a vertical position above the ground or zero height position)."

    Lever activities from Physics is Fun book:

      #1 - The Beam Balance
      #5 - The First-Class Lever (2 inch x 8 inch x 8 foot board)

      then revisit pan balance and find fulcrum

      (I didn't get to #2 The Law of the Lever or #4 What is the Mathematical Equation for the Law of the Lever?, but wanted to)

    Day Ten - Pulley

    more experimenting with the lever (discovering that my two year old Zac can lift me!)

    Lever activities from Physics is Fun book:

      #6 - A First-Class Broomstick
      #8 - A Second-Class Broomstick

      (I didn't get to #9 The Third-Class Lever or #10 A Third-Class Broomstick, but wanted to)

    picture books with pulleys -- use one to kick off the discussion

    explain the relationship between a pulley and a lever -- a pulley is a flexible lever!

    remember big distance = little F
    the more pulleys in the system, the longer the string, the less effort it takes to do the work

    Cable Car Kit from Nova Natural

    Block & Tackle from Nova Natural -- expensive but worth it!

    The Block & Tackle is really easy to put together with a group of kids because it is fast. You just run the rope through the four pulleys according to the diagram and hang it from a tree (using the included strap... absolutely NO TOOLs are needed for this) and add a basket. My six and seven year old students and I did this while the older children (ages 12 and 13) worked together and assembled the Cable Car Kit. The Cable Car Kit takes time to dry, and is a great accompaniment to The Lighthouse Keeper's Lunch.

    Note: The Cable Car Kit does require a Philips screwdriver and sandpaper.

    Day Eleven - Wheel & Axle

    Wheel & Axle activities from Physics is Fun book:

      #16 - The Wheel and Axle
      #19 The Crank

    A great way to explain this is a grocery store cart! I asked the kids if they've ever had to help carry the groceries into the house after their family has done a large shopping trip. Load after load. Bag after bag. It is a lot of weight! Yet their parent pushed all that weight around the store like it was no big deal...

    building on solo project (Egg Drop Challenge) with a small team project (Balloon Car Challenge in groups of 3) -- Balloon Car STEM Challenge: Engineering Design Process

    "it is easier to build an axle and then attach the wheels to it, then to have the wheels and then try to add an axle"

    "if the axle is too close to the container, the friction between the straw and the container will slow the axle from moving"

    Another Note: I purchased and drank a lot of the little Bolthouse Farms smoothies in the days around the Balloon Car Challenge, because the lids are perfect for wheels.

    Day Twelve - Inclined Plane, Wedge, and Screw

    Brainstorming examples of the inclined plane (ramp), we came up with the log which one student used as a ramp to help him climb up onto the lowest branch of the magnolia tree, a set of steps, and the ramp on the back of a moving van. One child pointed out that in helping her stepsister move to a new apartment, they used a dolly to move furniture up a ramp... an example of two simple machines combined (wheel & axle, inclined plane).

    I didn't buy a spring scale but it would have been helpful for this block, especially for activities like #22 What is the Mechanical Advantage of the Inclined Plane?

    Wedge activities from Physics is Fun book:

      #23 The Wedge

    Screw activities from Physics is Fun book:

      #26 A Model of the Screw

    biography of Archimedes in Mathematicians are People, Too: Stories from the Lives of Great Mathematicians, volume 1 - then we used 12 ft of clear 1/2 inch inside diameter plastic tubing and the 10 foot long piece of PVC pipe from the failed egg drop experiment (and this pipe can also be used for the third-class lever activity) to build an Achimedes water screw

    and it was FABULOUS!!!

    Archimedes is a great person to end week 3 on because some of his inventions for defending the port of Syracuse were totally ingenious... and kids are always inspired by his work to renew their creativity

Week Four

Construction Project: Building a Rube Goldberg Machine
Deconstruction Project: Taking Apart a Bicycle
Field Trip: Science Center
Field Trip: Local Design Studio (we picked Little River Research & Design)

    add last three simple machines to Main Lesson Book

    (we also enjoyed a great visit with Dav Glass from HackSI)

    follow up on the creativity/design process by reading The World Is Not a Rectangle: A Portrait of Architect Zaha Hadid
    what was it about her designs that made people think they couldn't be built?

    more optional fun which seems like it should fit in here somewhere, but I can't tell quite where: How Strong is Spaghetti?

    rewatch OK Go video... why does a little domino in the beginning end up moving a car? the potential energy is stored in it, the work is done by all of the workers who set that up, and the chain of motion is just unlocking it

    Now let's gather things from around the house and look over possible components for our Rube Goldberg machine:

    Personally, I really wanted our Rube Goldberg machine to include Pendulum Painting! But there's no really good way to take off the masking tape without using your hands

    other initial brainstorm ideas... it could end with an arm knocking out a pie pan from the Inertia Egg Drop and the egg could fall into the glass of water... or it could end by dropping a carrot into the rabbit's cage...

    NOTE: It definitely works best to start with your end goal in the Rube Goldberg Machine (ours was the cable car delivering a carrot to the rabbit) and then work backwards, planning interactions one at a time. We brainstormed and made a list of supplies we thought would be helpful (marble maze, PVC pipe, etc.) before we began.

I strongly strongly recommend using Trostli as your main text for the Physics blocks! Please also see my other page on Physics: The Physics Curriculum for Class 6, 7 & 8.

Elevator Physics: Newton's Laws is a nice helpful website!

Other resources we used were:

Blog posts from when I was teaching this block:

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