Test clothes pins to see if magnet placement affects the strength of how much weight the clothes pin will be able to support while attached to a refrigerator or metal door.
Glue one magnet onto the back of a clothes pin near the top thin edge, and set it aside to dry. Glue a magnet to the back of another clothes pin, near the bottom edge where the clothes pin opens up, and set it aside to dry. Glue a magnet to the back of another clothes pin just above the metal clip part, and set it aside to dry. Fashion a basket from a small paper cup and yarn, so that the basket can hang from the top of the clothes pin.
Mark a line on the magnetic surface where you'll place all three of the clothes pins. Open up the clothes pin, and start adding weight, such as basket. See which clothes pin magnets can support the most weight before moving down on the magnetic surface. Determine if the placement of the magnet impacted the amount of weight the clothes pin could support.
Test clothes pins to see if the number of magnets glued to a clothes pin directly related to the amount of weight it can support. Keep one clothes pin with only one magnet, and then create clothes pin magnets with two and three magnets.
Retest the amount of weight the magnet holds to see if there is a ratio between the number of magnets and the number of pennies the clothes pin will support before moving. Extend the test to see how many pennies the magnet can support before completely falling off the magnetic surface.
Show students how to make a catapult from a wooden block, clothes pin, ice cream stick and a plastic cap.
Glue clothes pins to the wooden block so that the thinner ends are near the end of the block. Glue an ice cream stick to the top of the clothes pin, right below where the metal clip. Glue a soda cap or small cup near the end of the ice cream stick, leaving a small edge where you can later press down on the stick. Allow the contraption to dry thoroughly.
Place a small object, such as a cotton ball or small toy, and press down on the ice cream stick "arm." Let go of the arm and watch the object fly through the air. Test to see which type of objects --- heavy or light --- fly the farthest, or hold a competition to see who can send things farthest.
Blow up a long thin balloon and clamp it closed with a clothes pin. Thread a five foot-long string through a straw. Tape the straw to the balloon. Secure the two ends of string between two points in the room, or let to people hold it up tightly. Position the balloon near one end of the string so that the clamped end of the balloon is near the end of the string. Unclamp the clothes pin and watch what happens.
The balloon should shoot forward like a rocket because the air pushes in the opposite direction as the air is released.