Tag: experiments’

Backyard Physics- Throwing Eggs

 - by KitchenPantryScientist

It’s getting nice outside. Time to start thinking about backyard science! Here’s one of our favorites, if you haven’t already tried it! W
IMG_2867

“Kids aren’t getting dirty these days. They’re not playing in the mud, not playing in rain puddles,” says Dr. Truglio, of Sesame Workshop in a Wall Street Journal article, about getting your kids outside.

Next to the kitchen table, my back yard (or front yard) is my favorite science laboratory.  It has the added bonus of being easy to clean up.  For this fun, messy experiment, a hose and a few paper towels do the trick. Make your kids clean up whatever mess they make!

My dad, who is a physicist, told me about this great demonstration. It teaches kids a little bit about motion and force while letting them do something that they are rarely, if ever, allowed to do- throw eggs!  All you need is a sheet, some clothespins or string, raw eggs, and some paper.  (You could use newspaper or easel paper.  It is just to make cleaning up easier.)  I also used a portable table turned on its side as a wall, but you could just use a wall or the side of a garage and have your child hose it off when you are finished.

Hang the sheet up from a tree, if you have one.  If you don’t have a tree, you could hang it from anything else, or have two tall children or adults hold it.  Then have two kids hold the bottom of the sheet up, or tie it to chairs  so it makes a J shape when you view it from the side.  The idea is to keep the eggs from hitting the ground and breaking.

IMG_2866

An object in motion wants to remain in motion. To stop an egg moving through the air, you have to apply force to the egg. In this case, the force will be applied by a hanging sheet, or a wall.

Throw a raw egg at the sheet as hard as you can. It won’t break because the sheet slows the movement of the egg as it comes to a stop.  The law of motion says that the faster you change the speed of an object, the greater the force applied to the object will be.  When you change the speed of the egg slowly, like the sheet does, it lessens the force applied to the egg and the egg remains intact.

Now, put some paper on a wall (or table like we did.) Throw an egg at the wall. You’ll see what happens when something stops fast.  Once again, the law of motion rules.  When you change the speed of the egg quickly, it stops with a lot of force.  SPLAT. This is my kids’ favorite part.

IMG_2873

This is why they put airbags in cars.  If a car is moving and hits something, causing it to stop very quickly, the airbag act like the sheet, slowing the person in the car down SLOWLY and greatly reducing the amount of force they might hit the dashboard with.

Record your results in your science notebook, if you want to. Finally, be sure to wash your hands when you’re finished experimenting and cleaning up.  Raw eggs can have  bacteria called Salmonella living in them and on them. Have fun!

Potato Maze

 - by KitchenPantryScientist

I almost always have a sprouting potato or two around my kitchen. I’ll buy a bag of spuds and only use part of it, leaving the rest to turn green and eventually end up in the compost.

Luckily, those orphan potatoes are perfect for a few science experiments. One teaches you a little bit about physics as you watch an object in motion (a drinking straw) remain in motion as you drive the flimsy plastic deep into a potato. The other, a potato maze, teaches you a little biology as you think about what a potato needs to grow.

We’d stabbed a straw into a potato before, but it worked shockingly well with the boiling potatoes we got from our farm share. The straws went all the way through! Click here to learn how to do the potato experiment yourself!

To make a potato maze, all you need is a sprouted potato, duct tape,some cardboard and a shoe box (or any cardboard box with a lid.) Cut out cardboard pieces the same depth as the box, tape them together, bend them and tape them inside of the box to create a maze.
Try to keep the walls of the maze the same height as the box and be sure to cut an opening at the far end of the maze so that light can get in at one end.
Put a sprouted potato or two in the maze. Close the box and seal any light leaks (other than the opening) with tape. (See photo at top for an idea of how your maze should look, but they’ll all be different and there’s no “right” way to make your maze! Just make sure there’s a direct tunnel between your potato and the opening!)

Place the box somewhere where it will get plenty of bright sunlight pouring into the opening. Wait a few weeks and check your potatoes. (You can check them more often if you’re impatient, but they won’t grow any faster.)

What happens to the potatoes?

They should grow towards the light, since plants need light to grow. Using a process called photosynthesis, they can change sunlight, carbon dioxide, water and minerals into electrical and then chemical energy, which allows them to grow into food for other living things. In the process, they also give off oxygen, the gas that we breath.

How do you your potatoes grow without food and water?

There are nutrients and water stored in potatos that allow them to start growing for a while without soil and water.