Sunday, May 10, 2020

May 11th Challenge #6 - Engineering for Kids (Twirling Twig Mobile)

Hi Everyone!  I hope you are all keeping safe and finding lots to keep you busy.  I hope you all had a terrific Mother's Day weekend - it was so wonderful to see that beautiful sunshine! I know you are all working hard on your Egypt projects but I have added an engineering challenge for you IF you have time and IF it looks like something you would enjoy!  If you get it done, please e-mail me a picture or post it on our class FB page.  I am missing you all and hope to see you soon. ~Mrs. Watson


There is nothing like the challenge of building a mobile that works. Watching objects sway and dance in a mobile is calming and pretty to look at. But here’s a little secret….mobiles are also full of engineering! Oh yes, that sweet mobile you are making is full of opportunities for you to learn about some basic engineering/physics principles including tension and the center of gravity. Read on to find out how!

Below you will see a picture of the tools you are going to need to complete this challenge.  If you don't want to wrap the sticks with yarn (or if you don't have yarn) you can paint the sticks instead.  Of course, if you want your sticks unpainted or unwrapped, that works too.


  • Step One Assemble your sticks. Choose three longer sticks that are about the same size that can form a triangle from.
  • Step Two Overlap the ends of two sticks at a roughly 60-degree angle. Cut a piece of string and knot it around the two twigs at the joint. Wrap the joint tightly and knot the end to secure in place.
  • Step Three Add the third stick to form a triangle and wrap and secure the joints as directed in Step Two.

  • Step Four Assemble your twigs in the order you would like them to hang. We arranged ours by size with the longest sticks at the top.
  • Step Five Cut a piece of string about 6” longer than you want the mobile length to be. Tie one end to the center of the bottom chord of the stick triangle.
  • Step Six Place the first stick about 2” below the bottom chord of the triangle. Wrap the long string around the center point of gravity of the stick and tie a knot.
  • Step Seven Important! Test your mobile after adding each stick. Hold up the triangle with one hand and pull down on the string with the other hand. You want your stick to be suspended roughly parallel to the ground. You need to pull the string taut to test this! If the stick is hanging at an angle loosen the knot and move it over slightly to find the rough center of gravity for the stick.
  • Step Eight Repeat Step Seven for the remaining sticks you are hanging.
  • Step Nine Add a weight to the end of your mobile! We added a rock but you can also add a pinecone or other decorative element as long as has some weight to it. This will help keep the string taut.
  • Step Ten Add a string to the top of the mobile and hang it!

You’re done! Watch those twigs twirl in the breeze!


If your sticks are still not hanging straightish when the center string is held in tension then try the following steps on each stick that is hanging at too much of an angle:
  1. First try adjusting the string to one side or the other.
  2. Make sure the knot is tight enough to hold the string, a loose loop will not hold the stick in place.
  3. Try twisting the stick at the knot to move the knot to either the top or side of the stick. If the knot is positioned on the bottom of the stick it will not hang properly.

Engineering at Work

Okay so while I love mobiles for their fanciful design I love them even more because they are wonderful demonstrations of some basic engineering principles. Here are some physics and engineering concepts you can talk about with respect to mobiles:
  • Center of gravity The center of gravity or mass is the point at which an object is perfectly in balance. This is not necessarily the middle point of an object if the object is not uniform in size. You may notice that sticks that are straight and roughly the same circumference throughout will have their center of gravity at the stick midpoint. But if you are working with any sticks that are bent or not uniform in shape, the center of gravity will be off to one side. For more information on the center of gravity check out this wikipedia article.
  • Tension and Compression The other secret to this mobile is the concept of tension. String and other cable like materials are wonderfully strong in tension but awful in compression. Tension is a force that pulls on an object.Compression is a force that pushes on an object. When you pull a string it become tight and can carry loads; when you push in a string it can’t hold a thing but instead bunches up. The mobile string gets taut the more weight is added on the bottom. When it’s not taut, the sticks tend to hang at angles but when the string is pulled tightly they should hang roughly parallel to the ground. See the demonstration image below.

  • More about Tension & Compression As I mentioned, cable works well in tension but not in compression. So what materials are the opposite i.e. work well in compression but not in tension? Concrete and stone. Ever wonder why you see buildings made of concrete with metal rebar embedded in the concrete? Well, concrete is amazingly strong when you push on it but if you were strong enough to pull it apart it would crumble. Enter rebar. Rebar are steel rods inserted as framework within concrete structures. Rebar, like cable, is super strong when you pull on it but bends if you push on it. Pair it with concrete and you’ve got the perfect match of materials to perform well under BOTH compression and tension.


I bet you never thought a DIY mobile was actually a engineering project…well now you know!
Have fun!  This challenge comes from the following webpage: 

Saturday, May 2, 2020

May 4th - Challenge #5 - Obstacle Course

Hello Everyone!

So, I checked the weather report for this week and it looks like the sun is going to shine for most of the week.  We hope you are all getting outside to get some fresh air and exercise during these strange times.

Your challenge for this week is to create a sidewalk/driveway/backyard obstacle course.  If you have a driveway or sidewalk you can use sidewalk chalk to create a course that includes things like; hopping, skipping, jumping, spinning, following a curvy/zig-zaggy path and maybe even a target station where you have to hit the target with an object (like tossing a ball into a bucket or knocking down a milk carton with a tennis ball).  If you don't have a sidewalk, then find some things around your house/yard to create a back yard obstacle course.

The challenge is to get you moving in ways you would not normally move in a day using items you have around your house or yard.  I have included a couple of sample courses. but these are ONLY to help you get an idea where to start - you choose your own activities within your course.

Below is a video (it's less than 2 minutes)  you can watch to help you get some more ideas.  I can't wait to see what you come up with.  It would be SO great if you could post a picture of you on the course you designed.


Monday, April 27, 2020

April 26 - Challenge #4 - Pop Art

Hello everyone!  Thanks so much to those of you who are participating in our challenges and, thank you to those of you who are sending pictures.  It's so great to see your smiling faces and it looks like you are having fun with these challenges.  So, here we go for this week.  This week's challenge is an Art Challenge.

Pop art became very popular in the 1960's.  It focused on portraying every day items in simple ways and bright colours.

Your challenge is to to create your own pop art.  Try to focus on the following aspects:

1.  Fold your paper into four sections.
2.  Draw or trace your main subject on to each of the four sections
4. Colour the background one bright colour, colour your subject in contrasting colours.



Sunday, April 19, 2020

April 19 - Challenge #3 - Create a Catapult

Hi Everyone!  Hope you are all doing well and staying safe.  I am hoping these weekly challenges are enjoyable for you.  The first week only 3 of you posted pictures and then this last week we were up to 6 students posting their projects so that is great!  I am really loving seeing both your projects and your smiling faces so keep those pictures and videos coming.

This week's challenge is to create a catapult.  There are some pictures below to give you some ideas but, as always, they are just there to inspire you and provide a starting point.  Any catapult, any size, with any materials you have around.  It would be BONUS if you could catapult an object towards a target and even BETTER if you can actually hit the target.  Have fun!


Sunday, April 12, 2020

April 12 - Happy Easter and Challenge #2

Hoping you all had a wonderful Easter 

Challenge #2 - April 13

As the sun is supposed to shine this week we are heading outdoors for Challenge #2.  My challenge for you is to create a backyard game that involves a target and scoring.  I have put a few examples below for you but as always, creating your own would be even better.  Once your challenge is complete, take a picture and send it to my e-mail ( or post it on our Coquihalla 2020 (BaM) Facebook page.  I can't wait to see what you come up with.  Have fun!


Monday, April 6, 2020

Challenge #1 - Get Outside

Hi everyone!

My challenge for you this week is to get outside.  We finally have a few days in a row that will be nice so I would like you to go into your yard, or on a walk in your neighbourhood with someone from your immediate family.  On your walk I would like you to gather interesting rocks, leaves, flowers, acorns or whatever else you can find to help you create a happy face.

Make the face somewhere in your house or yard and take a picture of it.  If you are able to, get an adult in your home to send it to me at .  I will do another blog with all of the pictures I receive.

I hope you are all finding ways to be amazed with the world around you as you spend this time staying safe.

I miss you all and can't wait to wave to you on Thursday when the teachers and staff of Coquihalla drive through your neighbourhood to say hello from our cars and trucks.

Here is an example of this first challenge:

Thursday, April 2, 2020


It's so nice to see you all - even if it's just in a picture!

I can't wait to connect with you all in the next couple of weeks.  It has been a weird Spring Break for all of us this year and I am keeping my fingers crossed that we will all be able to be together again soon.

I am wondering how you are all doing.  How are you keeping busy?  Are you able to keep in touch with each other?  I imagine the hardest part of staying home is not being able to see your friends.  This is true for me also - I am missing my family a lot even though we keep in touch in a variety of ways.

This space will be where I make suggestions for things you may want to try at home.  I want you all to remember that these are ideas for you that I think you will enjoy doing (and if you learn a little along the way, that is even better).  I would like it if you were able to send me pictures and/or notes whenever you want.  My e-mail is

I am keeping busy at home working on how and what is the best way to plan for you all.  I am also doing a lot of art and even some writing.  I keep a journal and I am writing things down about all of the strange things that are going on in our world.  I write poetry.  I draw pictures.  I ask questions.  I write my feelings.  These are all things you could do if you want to as well.  I am learning to paint things that my grandchildren love.  Here are a couple of pictures I have painted:

If you feel like you want to share some of what you are doing to stay safe and keep busy, I would LOVE to hear from you.  Thinking of you all and missing you more than you know.

Love, Mrs. Watson

May 11th Challenge #6 - Engineering for Kids (Twirling Twig Mobile)

Hi Everyone!  I hope you are all keeping safe and finding lots to keep you busy.  I hope you all had a terrific Mother's Day weekend - ...