My kids and I have commenced our annual Spring tour of Berkshire playgrounds, parks and hiking spots (keep an eye out for “Berkshire Grounds For Play” a new BFF blog coming soon). Last week we stopped at a park I pass a couple times a week without a thought. The play equipment is old-school, rusty in spots and utterly unchanged since I was in middle school watching, and occasionally keeping score on the chalk board, for my softball playing friends’ games.
I would have blown past the park again, but I had some time to kill before the Lee Prime Outlets opened and as we passed, my daughter shouted, “Mommy, There’s a giant slide and a playhouse for us to play Peter Pan and Captain Hook!” So we swung into the parking area at East Lee Park. (Note: There is nearly identical play equipment at the South Lee Park, Marble Street playground and the Lee Athletic Field.)
They ran straight for the towering non-OSHA or MOM-certified, 8-foot high metal slide, but once they realized friction increases over time, they headed for the next most dangerous attraction, the rusty, red and yellow teeter-totter.
My daughter hung suspended six feet in the air, with her brother’s bum planted firmly on the ground as he chanted “Argh, Argh, Argh. I’ve got you. Time to walk the plank!” When she screamed, “Peter Pan, Peter Pan, I need you,” the Math Mom in me kicked in. I started spewing out a physics lesson on levers, force, body mass and distance from the fulcrum, all of which was drowned out by her screams as he repeatedly bumped the see-saw on the ground, bouncing her off of her seat.
Finally I yelled, “If you want to get down, slide your bum back as far as you can.” And, as she followed my instructions, Captain Hook began to rise into the sky kicking and screaming, as his bum slid forward (closer to the fulcrum). Once the roles were reversed and he wanted down and she wanted up, the “teaching moment” was in full swing with me instructing one to move forward and the other to slide back as they quickly got the hang of it and I had an idea for my next “Math Mom” column!
So let’s begin by going over the knitty-gritty physics of levers, so we can get back to the fun!
By definition, a lever is a simple machine with a rigid bar that pivots about a fixed support, called a fulcrum. It is used to reduce the effort of moving a load (resistance) at one end when pressure is applied at the other end. Most playground see-saws are levers that move about one central fulcrum. A force applied by pushing down on one end, results in a force pushing up at the other end (1st class lever).
Swings and springy ride-on playground toys are also levers because applying force causes a load to pivot about a fulcrum, which in this case is at one end, rather than in between the load and the force. Many parts of the human body are also levers. Your hand applies a force to pivot loads about your elbow (the fulcrum). Your hip pivots to allow your leg to swing and kick a soccer ball. We are surrounded by levers in our everyday life — forks, hammers, staplers, shovels, windshield wipers, scissors, wheelbarrows, salad tongs, baseball bats, brooms, hockey sticks, hairbrushes, rakes, toy dump trucks or backhoes, bicycle peddles, nail clippers, and doors swinging on hinges just to name a few.
BUT, the absolute best place to experiment with these simple machines is at the playground!!
This Activity Can Help to Enhance:
– Counting Skills – Math vocabulary
– Understanding of mass, loads, and the cause/effect relationship between balance and the distance from the fulcrum
– Inquiry skills – Observation skills
– Coordination and muscle development
– Playground with a see-saw, swings and/or springy riding toys
– Craneville Elementary, Park Ave, Dalton (3-fulcrum wavey see-saw)
– East Lee Park (Rt 20)| Marble St Playground | Athletic Field (Housatonic St) in Lee
– Interlaken Park, Averic Rd (off Rt 183), Interlaken
– Pinegrove Park, Curtis Ave, Dalton (springy seesaw)
– Lee Elementary School, Greylock St, Lee
(single fulcrum, 4-way see-saw & four awesome springy rides)
– Kittredge Elementary, Rt 143, Hinsdale (double fulcrum, 4-seater see-saw)
NOTE: There are also many parks in the Berkshires with cool springy ride-on toys! (Whitney Farms (Cheshire), Greenridge Park (Dalton), Hinsdale Town Park, Stockbridge Town Park, Pinegrove Park (Dalton), Lee Elementary School).
Let kids experiment with the science of see-sawing. When one child outweighs the other, instruct the lighter child to move further back in the seat and the heavier one to move forward. Place two smaller children on one end to balance one older child or one small child and one larger child per side. The more you experiment, the more they will intuitively pick up on the way to balance masses at either end of a lever, based on the distance from the fulcrum.
ACTIVITY ENHANCEMENT IDEAS:
Build your own see-saw using a 12-inch ruler and a fulcrum (a magic marker or round block will do the trick). Experiment with your mini see-saw by balancing blocks or toys and moving the fulcrum around. Try counting the inch marks off together to twelve and then finding what number is “1/2-way” to twelve by placing your fingers at either end and counting toward the middle (0&12, 1&11, 2&10, 3&9, 4&8, 5&7, 6!!). This is a great way to introduce simple addition and subtraction, as well as the idea of fractions. Try the same technique and say “Plus 1 is 1, minus 1 is 11, plus 1 is 2, minus 1 is 10… So 6 is in the middle or 1/2 way to each end.”
Construct “upside down see-saws” by tying a string to the center of the ruler, a yard stick, household items or things found in nature and slide the string to the best position for balancing it horizontally. Then try hanging items on either end. You can build on this idea to create a mobile or homemade scale.
Ask your child to name more example of levers that your family uses in everyday life. If he/she has any trouble coming up with ideas, you can get the ball rolling by asking a few questions.
– What do we use to help clear the snow off the front walk in the winter? Do you think the snow would be easier to move using a shovel with a short handle or a long handle? Then find a sandbox or sandy beach and test your hypothesis!!
– How do you think this door swings open without scrapping the floor? Is it easier for you to open the door by pushing by the doorknob or near the hinges?
– How does a builder pull a nail out of wood? Does she use her hands?
– Direct their attention to a heavy object or piece of furniture. Ask them to try to move it using one finger, then try it with their arms and finally have them sit in the floor and push with their feet. Which way was easiest? Why do you think?
READ ALL ABOUT IT:
Hop! Plop! by Corey Rosen Schwartz and Tali Klein
The Teeter-Totter, by Joy Cowley
How Do You Lift a Lion?, by Robert E. Wells
Simple Machine: Wheels, Levers and Pulleys, by David Adler
On the Seesaw Bridge, by Yuichi Kimura