Science Activities

Static Electricity
1. Bending Water (tap with running water, and comb)
Create static electricity on a plastic comb by combing your hair or you can rub a plastic rod with some wool. Turn on the faucet so that the water runs slowly but smoothly without breaking up. Bring the comb near to the running stream of water without touching it. Watch what happens..

2. Experiment with balloons (balloon, felt, timer, water source)

Blow up the balloon. Rub one side with the felt or your sweater to create static electricity. Place the balloon against the wall. What happens? Time how long it lasts. Try it again after someone has had a shower, or you spray water on the wall. What’s different? Why?

Float or Sink?
Materials:clear plastic or glass container, water, vinegar, baking soda, food coloring, items
Almost fill the container with 3 parts water and one part vinegar. Be sure to leave some room at the top of the container. Slowly add one teaspoon of baking soda, very slowly! Too much at one time and it will all bubble over the top. Have a towel handy if the kids are adding the baking soda! When the bubbles settle down, slowly add a second teaspoon of baking soda. When the bubbles settle, add a few drops of food coloring. Notice the the liquid is moving and quickly mixes in the color. Now comes the fun part. Find some interesting items (raisons, rice, dried fruit or vegetables, broken bits of spaghetti, pieces of fruit - grapes cut in half). Will the items float or sink? Drop in a few of the first item. Usually they will sink to the bottom. Wait a few minutes and then they will rise to the surface, then sink again. Rice almost seemed to dance. It is fun to watch for hours and just observe how different items react. If the movement seems to be slowing down, add another teaspoon of baking soda.
What is happening?
The vinegar is an acid and the baking soda is a base. When you combine them, a chemical reaction produces carbon dioxide. The carbon dioxide bubbles build up on the surface of the object. When enough bubbles attach to the object, it floats to the surface and releases the gas. Then it sinks back to the bottom to start the process again.

Airplanes
How does an airplane take off?
When an aircraft moves into the wind, the wings cut the airflow in half. Some air travels above the wing, some air travels below the wing. Plane wings are build to be curved on top and flat on the bottom. The wind, or air stream, flowing over the wing travels a different path from air traveling under the wing. This difference in the path of the wind, creates lower air pressure above the wing. The higher air pressure under the wing lifts the plane into the air creating lift. When there is enough lift to overcome gravity, the plane takes off. All the time, the plane is being slowed down by having to push through the air. This is called drag, and the engines have to overcome it. As long as the plane continues to move forward at a fast enough speed, the plane continues to fly. Planes use engines to move quickly down the runway to create the lift for take off. Helicopters rotate their wings (or blades). The rotating motion forces air past the wings creating lift.

Experiment with Flight
1. Make a Wing (Paper, tape, thread, needle, and pencil)
Cut the paper 15cm x 5 cm or 6in x 2in. Fold the paper 8 cm or 3.25 inches from the end. Roll the longer end of the paper evenly around the pencil to make it bulge. Tape the ends of the paper together so that it creates a wing shape (flat on the bottom, and curved on the top). Thread the needle and push the thread through the wing, about a third of the way back from the curved end. Remove the needle from the thread. Hold both ends of the thread and blow over the front end of wing. The air flowing over the wing, creates lower air pressure above the wing, so it rises up the thread.

2. Experiment with balls (two ping pong balls, thread, tape, drinking straw)
Cut two pieces of thread. Tape a piece to each ping pong ball. Hang them from a doorway so they are about the height of your mouth and the distance between the balls is 2 cm (or 3/4 of an inch). Use the straw to blow on one ball. The distance between the two balls increases. Now try aiming the air between the two balls. Watch what happens? Why?