For Kids!

Aye, Aye Captain!

// September 9th, 2013 // Comments Off on Aye, Aye Captain! // For Kids!

Engineer a “berry” awesome juice powered boat, and enjoy sailing the seven seas all month long!

 

Here is what you’ll need:

2 Styrofoam plates     boat supplies

1 Styrofoam cup

1 Styrofoam bowl

1 Bendy straw

Tape or glue

Your favorite juice

Water

Pool or tub filled with water

How to construct your boat:

1. Glue or tape the 2 styrofoam plates together face to face.  The edges should meet.

2. Attach the bowl upside down to one of the plates using tape or glue.

3. Near the bottom cup, poke a hole just big enough to fit the straw through.

4. Glue or tape the cup to the bottom of the bowl.                                                                                                                                             juice powered boat

5. Stick the short end of the bendy straw through the hole in the cup.  The longer end of the straw should point down.

6. When the glue dries (if you used it), decorate your boat.

7. Place your boat into the pool or tub, and add water to the cup.  The boat should begin to glide across the water.

8. Once the water has emptied from the cup, fill the cup with your favorite juice.

9. Observe the boat’s speed differences when using water compared to using juice.

How does the boat work?

When you place liquid into a cup, it pushes on all sides of that cup.  By poking a hole in the cup, you create an area in which the liquid can no longer push on.  However, the water still pushes on the other areas of the cup, and this force propels the boat along the water until all of the water has left the cup.

Water molecules have an attraction to each other, called cohesion (the tendency of molecules to stick to one another), and that property gives water its’ surface tension.  If you look closely at an area of water, such as a pond or bathtub, you can see a skin-like film across the surface of the water.

When you add juice the cup, and the juice comes out of the straw and into the pool or tub, it breaks the water’s surface tension.  Since juice molecules are not the same as water molecules, they will not stick to one another.  The breaking of the water’s surface tension will make the molecules pull away from each other, and anything on the surface will move with the molecules, therefore, making the boat glide faster!

Summer Solar S’mores!

// November 13th, 2012 // Comments Off on Summer Solar S’mores! // For Kids!

Engineer your very own solar cooker, and enjoy these delicious treats all summer long!

Here is what you’ll need:                                                                                         

Summer Solar S’mores!

  • Pizza Box
  • Tape
  • Black Construction Paper
  • Ruler
  • Plastic Wrap
  • Scissors
  • Aluminum Foil
  • Glue Stick
  • Bamboo Skewer
  • S’more ingredients (graham crackers, Hershey chocolate bar, marshmallow)

How to construct the solar oven:

 1. Assemble the pizza box (if a new box) and open it.

 2. Glue aluminum foil to the inside bottom and sides of the box.

 3. On the top of the pizza box, measure and draw a square with the edges 1” from the sides of the box.

 4. Cut three sides of the square to form a “flap.” Do not cut the fourth side, which is closest to the back edge of the box.

 5. Fold back and crease the fourth side. This side will act as a hinge.

 6. Glue aluminum foil to the inside of the flap, shiny side out, as smoothly as possible. This will be your reflector and will reflect sunlight into the oven.

 7. Cut a piece of plastic wrap big enough to fit over the opening of the flap.

 8. Tape the plastic wrap tightly over the opening, to secure all four sides. You will have to tape it to the hinge-edge of the flap.

 9. Cut a second piece of plastic wrap big enough to cover the flap, and tape it to the underside of the pizza box top. Stretch it tightly, and tape it securely on all four sides. This will give you two layers of plastic covering the opening of the flap, making a window.

 10. Tape the sheet of black construction paper in the center of the inside bottom of the box. It will be on top of the aluminum foil.

 11. Seal the outside edges of the box with tape to prevent any air from leaking in. Make sure you can still open the top of the pizza box to place your food in it!

 12. Use a skewer, with one end taped to the edge of the flap, to prop open the flap. This way it will be adjustable to allow the maximum amount of sunlight to reflect into the window.

Inside/Bottom of Solar Oven

 

 

 

 

 

 

 

How does a solar cooker work?

The solar cooker uses natural sunlight to heat up the yummy s’mores!  It works best  when it can collect and concentrate the light to a specific area.  The aluminum foil on the flap is reflecting the light onto the food, while the black construction paper helps absorb the heat produced from the light.  To start “cooking,” the heat produced must be kept inside the box.  The plastic wrap window acts as an insulator, and retains most of the heat inside the box.  Some solar cookers are very effective, depending on the size of the box, and how many aluminum reflectors are present. 

Thirsting for another solar cooker activity? 

Check out EnergyQuest’s activity on the following site, and learn to build a solar hot dog cooker!

http://www.energyquest.ca.gov/projects/solardogs.html

Solar Hot Dog Cooker