Before I had kids, I taught science to groups of homeschoolers (grades 1-6). Thankfully, I saved all of my lesson plans, and now I am able to pull out ready-made units for my kids!
I just started a unit on Force and Motion with my older two boys (4th grade and 1st grade). We have been studying land animals with our science textbook from Apologia: Exploring Creation with Land Animals of the Sixth Day, and we LOVE it. However, there are not a lot of experiments that can be done with animals, and force and motion lends itself well to lots of hands-on fun, so it’s a nice break. I’ve also found that it works well to do something high-interest like this right before a holiday break!
During our first week, we learned about energy. Energy is the ability to do work. We learned about the difference between potential energy (stored energy), and kinetic energy (the energy of moving things). Our ping pong ball shooters were the perfect thing to learn about potential and kinetic energy! When you stretch the balloons, they have potential energy, and when you release them, they have kinetic energy which they transfer to the ping pong balls, thus shooting it across the room.
Then we did an experiment to further study the transfer of energy from one object to another.
I got this experiment from a book called “Force and Energy” published by Instructional Fair that appears to possibly be out of print. It looks like Instructional Fair was bought out by Carson Dellosa, and I can’t find the book on their site or on Amazon.
For this experiment, all you need is a ruler with a groove in the middle and some marbles.
First, we lined up two marbles in the middle and one marble at the edge. I asked the boys what they thought would happen when I flicked the marble. They thought that both marbles in the middle would roll away.
Surprise! Only one of the marbles rolled away!
We repeated the experiment with different configurations of marbles (like shooting 2 at 3), and pretty soon the pattern emerged: the number of marbles that you flick equal the number of marbles that roll away. In other words, the rolling marble can only transfer the amount of energy that it has – one marble can transfer energy to one marble, two marbles can transfer enough to move two marbles, etc.
Then the boys wanted to see what would happen if we flicked one of our larger marbles:
When we flicked the large marble at four smaller marbles, two marbles rolled away and a third marble rolled slowly away. We decided that the large marble had approximately the energy of 2.5 of the small marbles.
If you like this experiment – stay tuned! Posts to come over the next few weeks with experiments on friction, inertia, momentum, and more!