GMD: STEM challenge
PRINCESS ANNE, Md. – STEM educator Brad Hartle at the University of Maryland Eastern Shore put WMDT’s Jake Grant and Jordie Clark through an Engineering Challenge Olympics- the ultimate STEM challenge.
All of the experiments are ones families can do right at home.
Bridge Build Challenge:
Materials Needed (Can be adjusted to your designs):
– Popsicle Sticks/Tongue Depressors (Approx. 14)
– Popsicle Stick with Holes (1)
– Craft Sticks (Approx 20)
– Tape (Duct Tape is preferred)
– Scissors
– String
– Some weight, such as a bucket to pour sand in
– Something to span the bridge between like two tables or two chairs
Steps:
1. Collect all your materials
2. Depending on your materials, build the base of your bridge.
a. In this instance, the popsicle stick with holes goes in the center, with two regular popsicle sticks on each side
b. Another five popsicle sticks go together at the end of the one with holes
c. The last five popsicle sticks go together at the other end of the one with holes
d. Thus forming a three popsicle stick long base by five wide
3. Use the craft sticks to build your supports, truss, beams, etc…
4. Once you have built the bridge, use your selected weight to test the bridge
a. Start with the low weight and build up until the bridge falls or breaks
Wind-Powered Car
Materials Needed (Can be adjusted to your designs):
– Cardboard
– Wheels (can find different types of Amazon or at a craft store)
– Skewers or something to use as the axle to connect the wheels
– Tape
– Scissors
– Different Types of Paper
– A Box Fan or something similar to produce wind
– Straws or something else to fit your axle through
– Additional materials like pipe cleaners – make it fun
Steps:
1. Cut the cardboard to a size that your axle can span across
2. Using something like a straw, connect your axle to the cardboard
a. The straw allows you to connect to the cardboard without stopping the axle from moving
b. Test to make sure the axle can still rotate
3. Attach your wheels to the axle.
a. Test the car by just pushing it on a table or floor to make sure the axle rotates and, in turn rotates the wheels
4. Now start building your sail or wind catcher
5. Once you have a nice sail/wind catcher setup, your race track
a. Pick a smooth surface and mark a starting point for the car
b. Pick a spot where your box fan will stay.
6. Place your car at your starting point and turn on the box fan
a. See how far your car travels
7. Now have fun adjusting your wind catcher to see if you can keep the car in a straight line and travel further than your initial attempt.
Elephant Toothpaste
Materials Needed:
– Hydrogen peroxide (H₂O₂): 3% or higher (the higher the concentration, the more dramatic the reaction, but handle with care and have adult supervision)
– Dish soap – Liquid dish soap works best
– Food coloring – Optional, for colorful effects
– Yeast – One packet of dry yeast or a tablespoon of active yeast
– Warm water – To activate the yeast
– Plastic bottle or a container – 12 oz or 16 oz bottles work well
– Baking sheet/tray or similar to contain the mess
– Gloves and safety goggles – For protection
Steps:
1. Set Up Your Area:
– Work in an area that can get messy. Place your plastic bottle on the baking sheet or tray.
2. Prepare the Yeast:
– In a small cup, mix one packet of dry yeast with about three tablespoons of warm water. Let it sit for about 5 minutes to activate.
3. Mix the Ingredients:
– In the plastic bottle, combine about 1/2 cup of hydrogen peroxide and a squirt of dish soap. If you want to add food coloring, mix a few drops in now.
4. Add the Yeast:
– Once the yeast is activated, pour the yeast mixture into the bottle with the hydrogen peroxide and dish soap.
5. Watch the Reaction:
– Step back and observe as the reaction occurs! You should see a rapid foaming action that looks like toothpaste being squeezed from a giant tube.
6. Clean Up:
– The foam created is just soap and water, so it’s safe to clean up with a cloth or sponge. Dispose of the leftover materials appropriately.
Safety Tips:
– Wear gloves and goggles to protect your skin and eyes.
– Experiment in a well-ventilated area.
– Do not ingest any of the materials used.
Explanation:
The reaction occurs because the yeast catalyzes the breakdown of hydrogen peroxide into water and oxygen gas, producing a large volume of foam as the soap captures the oxygen.
