What a wonderful opportunity to study physics and engineering outdoors in the yard or schoolyard!
How does a shovel work? And a trowel?
Now experiment with several kinds of the same tool and discuss why each one works and which you find optimal. Then design your own tools....
A wheelbarrow is an example of a machine that uses a lever and wheel/axle.
Do some testing in your yard with different wheelbarrows and garden carts.
With the Smart Cart and garden cart I can carry a load single-handed, up and down an inclined plane, with two wheels. The Smart Cart is much easier to use than the less expensive garden cart.
With the wheelbarrow: I need two hands to carry the same load, and I need to do more work for the same load, but I only have one wheel to look after.
- Discuss with your students the pros and cons of one and two wheels.
- How well does each machine steer?
- What happens when you want to put down your barrow?
- Which machine is more stable?
- How do the wheels differ in size, and tire, and maintenance?
- Try the balance with different distributions of load?
My 7 cu ft light green garden cart cost about $120
My 6 cu ft wheelbarrow cost about $85
My 4 cu ft wheelbarrow cost about $35-40
My 2 cu ft red wheelbarrow cost about $30
What is the triple bottom line for the various criteria: economic, environmental and social?
As an adult, I much prefer to use the dark green Smart Cart: I decided to base my decision not on cost alone, but how well it does the job of moving my load from point A to point B, and other criteria such as looks, mechanics and durability.
My kids K-5 give their thumbs up for the little red wheelbarrow. And they also like the balance and ease of the big Smart Cart!
http://www.realschoolgardens.org/Libraries/Documents/STEM_in_the_Schoolyard_-_Simple_Machines.sflb.ashx
Buy wheelbarrows and garden carts at your local hardware store.
Buy Smart Carts online at http://shop.mullerscarts.com/utility-cart/
No comments:
Post a Comment