Tuesday, July 26, 2011

Race car ramp

All you need is a paper towel tube, some packaging tape, a raised surface, and a smallish object that rolls (but not too small...don't want anyone to choke).  We used a decent sized bouncy ball and a matchbox car.

Cut the paper towel tube in half and tape together with packaging tape.  Place to your desired height on a raised surface.  Race away!

Here's a video demonstration for you.

J plays California ramp in the middle (earthquake) - but that's the joy of this experiment - kids can take apart and fix the ramp to their heart's content.

Things to play with and consider:
*Height of ramp
*Where you start the object on the ramp (related to height too)
*Weight of object
*Type of object rolling
*Surface the object ends up on after the ramp
*The ramp might tip depending on slope of the ramp and momentum of the car - it's a very cheap yet entertaining science project, so no complaining.  If it bothers you too much, change where you start your object, change the angle of the ramp, or tape down the underside of the ramp.

Concepts(in case you have a really curious 2 year old and want to sound smart to your child and give him/her new vocabulary)

Transfer of Energy:

  • Potential Energy is mass x gravity x height (an object placed up high will potentially fall down), the higher it is or the heavier it is, the more potential energy it has.
  • Kinetic Energy is 1/2 x mass x velocity squared (kinetic is a fancy term for "motion" - once in motion, an object has velocity)

In an ideal world, the energy will transfer perfectly, meaning Potential Energy = Kinetic Energy, for our ramp set-up.  However, our world is less than ideal.  We have to deal with losses, mostly due to friction, which is the roughness of our surface.  Measuring losses would be another lesson for a little bit older age group (we did it in college physics) but it is doable with knowing all your variables listed above (you can measure velocity with photogates).***

*What happens when you raise the ramp or start the object higher on the ramp?
*What happens when you try a different object on the ramp?  Which object rolled better?  Why do you think that is?
*What happens when you put your ramp on carpet vs. tile?  Maybe you can measure the differences.  This is where you can mention friction and why the object didn't roll as far on the carpet though you started it in the same place.

Race away, my friends!

***Just in case you want to be challenged
Energy Equation: P.E. = K.E. + E.Losses,
so algebraically: E.Losses = P.E.-K.E.

Saturday, July 23, 2011

Nerdy Toy Airplane

"What was I thinking?" I asked myself on the car ride home after the purchase. I just bought J a toy with 25 pieces!! The alternate toy was a Little People knock-off airplane with 3-4 parts (the airplane and a few people). That was the toy J initially wanted, but I couldn't talk myself into spending a ridiculous amount of money on a toy where you just put people in and out of the airplane...BORRRRING!! Instead I kept looking in the store and found a very similar looking airplane that you could assemble and disassemble with its very own play power tool!  If that's not a fun toy, I don't know what is!  We talked J into that toy instead.  It wasn't a tough sale at all...

J couldn't wait to get home and try the new toy.  Here's how we spent this afternoon.

Mommy demonstrating

J's turn
(Note: tongue = concentration)

Almost ready

My proud Engineer-In-Training!

**Note, I have a fun, new experiment on the way.  It's a video demonstration.  It should be posted hopefully tomorrow or Monday.  My video editing software freezes my computer.  I blame Windows.

Monday, July 18, 2011

Doing science

All weekend, J was running around the house saying, "Doing science!! Yay!!  Yay!!  Yay!!"  This was about as good as I could get on camera.  I am soooo happy that J loves science so much.

Friday, July 15, 2011


Don't be afraid to use scientific language, like "experiment," around your child.  It's such a cool word that doesn't need to be explained verbally in kiddie terms.  It's an action word that should be shown over and over again.  Though if your child keeps asking you, a good way to explain it is "to see what happens."  Don't forget to use the word "hypothesis" or a "guess what you think will happen" before the experiments.

Here's an overview of the activity at J's school with the 4-5 year olds:
*Sink Float Experiment - kids were very enthusiastic and were able to guess which ones would sink and which ones floated.  There were some surprises.  This took a good 15-20 minutes of time.
*Submarines - the kids had a really good time, despite the rolls of pennies falling off of the submarines, the pennies covering the holes, and the straws popping out.  Most of them were able to get their submarines to sink and blow into the bottle to get it them to resurface a few times.  They got to take it home.  I'm hoping they use them as a new bath toy!

Some improvements: wrap the pennies in foil so that the rubber band doesn't slide off as easily.  Hot gluing the rubber bands down might help too.  The clay wasn't ideal, but I wasn't going to drill holes through the caps.  Maybe, I'll try that for next time.

On Saturday, I took J downstairs to collect rocks and leaves for our sink/float activity that I just completed at his school.  One of our neighbor girls was outside and joined in on the treasure hunt.  She's very inquisitive, and I told her we needed the rocks for an experiment at J's school.  Her mom told me that she won't stop talking about the "experiment."  We're now set for a playdate for the same experiment for this weekend.

Sunday, July 10, 2011


I volunteered to do science with the 4-5 yr olds at J's school this Friday.

Here's a preview of what we'll be playing with: Submarines.

I will do Sink/Float with the kiddos first.  I collected a bunch of items and will have three separate bins.  One bin for "sinks", one for "float", and the third bin is for "depends".  They will "hypothesize" which items will sink and float.  Then they will test their hypotheses.  I'm hoping to use "depends" as the conversation starter about water weighing down objects.  Sponges and cotton balls are two examples of things that float until saturated with water.  We will then test some water bottles (also a "depends") to see if we can make them neutrally buoyant.  Then we'll do a modified submarine lesson from the link above...main difference is attaching the straw with clay instead of poking a hole through the cap.

If time, we'll play with the weight (pennies) and see if we can get the submarine to hover (the pennies + water actually weigh it down so it sinks fully).

Main Questions:
1.  What makes the submarine sink? (weight = water + pennies)
2.  What makes the submarine surface? (air, it's lighter than water)
3.  What makes the submarine hover in the middle of the water? (the perfect balance of water+air)

I did something similar with the 3rd-5th graders at a summer camp I taught at 6 years ago.  They used whatever recyclables they brought in from home for their submarines and had a few lead-up activities to where they were really understanding buoyancy.  The difference: I let them design their own submarines.  We also used balloons to help the submarines surface.

***Note: many water bottles are now more "eco-friendly."  They do not make ideal submarines anymore since they crumple easily when a rubberband is wrapped around them.  However 20-oz diet soda bottles work wonderfully!  I better get to drinking!

Wednesday, July 6, 2011

Pooh Sticks

I don't know if that's what this game is called, but it's what I first called it and what J's uncles first said when they realized what we were playing.  The idea for this week's science came from Winnie the Pooh (I don't remember which one - they all blend together).

We were waiting around Ashland while J's daddy, uncles, and gpa went mountain biking.  After about an hour of playing in the park, J got anxious.  We went on a walk where we met a very odd man who gave J a stick.  We graciously accepted the stick but by the next bridge didn't want more to carry, so we showed J what happens when we throw the sticks over the bridge and into the water.  We then spent the next hour gathering sticks and leaves and tossing them off of the side of the bridge.

Topics covered in "Pooh Sticks"
Fluid dynamics/mechanics - flow of water.  What happens to the sticks in currents or around obstacles like rocks?  How do different items (ie leaves, rocks, sticks) react differently to the water.
Transfer of energy - things falling from bridge - transfer of potential (things "potentially" fall) to kinetic energy ("kinetic" is a fancy term for motion - so once it's falling it has motion and kinetic energy).
Trajectory motion - throw things off of the bridge.  Can you hit targets right off the bat?

The original "Pooh Sticks": pick unique sticks per person.  Have everyone drop them off the bridge at the same time (drop them so the sticks end up going down stream and under the bridge).  Run to the other side of the bridge and see who stick wins the race under the bridge.
Targets: who can get their stick to hit a rock (or other target) after you throw it in the river?
Different objects: try throwing different objects into the river.  Note how each react.
Find the coolest stick!: the name says it all and if your child is like mine, it will take up to 15 minutes of time.
Name colors of sticks/leaves/rocks/anything you see off the bridge: colors are a very small portion of our electromagnetic spectrum.  Why not start nerdying up your child now getting him/her to memorize names and wavelengths?  I'm only somewhat joking.