Need for lesson - String, duct tape, jumbo paper clips, objects of different weights that can be hooked onto the paper clip (key chains, keys, washers, nuts, chain links), a yo-yo, and a picture of a grandfather clock.
can be pasted onto an index file card for quick reference
Prepare - Make sample pendulums by taping one end of a pieces of string (various lengths) to the edge of a table and putting an object on the other end of the string that has a paper clip hook on it.
A pendulum is a weight hanging from a fixed point. A yo-yo on a string can be pendulum (demo). On a swing, you are a pendulum. A place pendulums can be found is in clocks because it takes the same amount of time for it swing in one direction as it does for it to swing back in the other direction. Back and forth, back and forth, or tick tock, tick tock. Here is a picture of one. Notice the pendulum hanging inside of the clock.
Let's swing this pendulum (taped to the table) that we made and watch what it does for a minute.
The weight at the end of the pendulum is called a bob. The swinging back and forth is due to gravity. The time it takes to swing over and then return back to its starting position is called one period. We have different objects to hang on the pendulum. Let's try this one (take a few turns using different objects and observe the swinging motion.) Do you think the objects that were heavier take the same time to swing as the lighter objects? Is the motion the same or different with the different objects? What about the length of the string, does a pendulum with a long string take the same time as on with a short string?
We can take turns exploring with these pendulums taped to the table. (set up an area for children to have fun and explore the pendulums with the various objects)
Salt Pendulums - Make a funnel salt pendulum. Make a funnel with paper and attach to a doorway using three strings. Lay black paper on the floor in the doorway. Add salt to the funnel and swing it. Children can watch the shapes and design the pendulum with the salt as it falls out of the paper funnel.
Paint Pendulums - Children can make paint prints using a pendulum.
Need for lesson - Enough string pendulums having a washer as the bob for each child.
Pendulum Rhyme - Each child holds onto their pendulums and swings them as you say the rhyme: (from 474 Science Activities)
swinging to and fro,
first it swings so very fast
and then the swinging slows.
Try singing different songs to the swinging of the pendulums such as Twinkle Little Star or ABC's
Have a review of any materials, songs, or other lessons from this month; Asia, motion, Einstein.
Have a snack of hummus and naan while listening to some music from India!
Older children can play Parcheesi!