Students at the middle or high school level may need to make an egg drop contraption for a science project. Egg drops are popular experiments that challenge students to think critically and design a contraption that protects an egg when dropped from a certain distance. Egg drop contraptions can take many forms to achieve the same goal: to decrease the force of impact, whether by distributing force or by decreasing the force of gravity.
A box of cereal and some plastic bags are all you really need to make a successful egg drop contraption. Light, crispy cereal, such as crispy rice cereal, works particularly well because it crushes easily. Fill four or five sandwich bags with cereal and place these around the egg inside a larger plastic bag, ensuring the egg is cushioned on all sides. This should work well for a standard two-story drop, but use larger bags and more cereal as the height of the drop increases. When the bag hits the ground, the impact of the landing is absorbed and distributed throughout the cereal. You’ll probably end up with a bag of crushed cereal, but the egg should be unbroken.
People are able to jump from planes with parachutes and land on the ground safely because the parachute creates air resistance, which works against the force of gravity to slow the rate of the fall. The same principle can be applied to create successful egg drop contraptions. Place the egg in a lightweight box with a lid and tie the parachute to the box with some thread. You can also try using a plastic grocery bag for the parachute and adding padding to the box. Remember that the larger and heavier the container, the larger the parachute will need to be to protect the egg. This may not work so well with egg drops of only a few feet, because the parachute needs time to open and generate air resistance.
"Oobleck" is a nickname given to a mixture of corn starch and water that forms a non-Newtonian fluid, i.e., a fluid whose flow does not have a constant value of viscosity. When it is at rest or when you apply gentle pressure to the fluid, it acts as a liquid, but it quickly becomes a solid when under more pressure. To make the contraption, combine two parts corn starch with one part water to fill a quart-size plastic bag. Then simply stick the egg inside the bag and let it fall to the ground. When the bag hits the ground, the oobleck forms a solid around the egg so that the force of the fall is evenly distributed around the shell's surface.
A simple padded box may likely be the most common successful egg drop contraption. The box you use should crush on impact, so use a material like cardboard instead of plastic or metal. You can line a box with any cushion or soft material, such as foam, sponges, bubble paper, cotton or marshmallows. Egg crate foam works particularly well, because its shape is perfect for holding the egg in place. Ensure that you have enough padding in the box to cover the egg evenly on all sides. When the box hits the ground, the force will cause the box to crush, which absorbs much of the shock of the fall. The force is also evenly distributed throughout and absorbed by the cushioning material.
- University of North Carolina Summer Institute for Engineering and Technology Education: Egg Drop
- ScienceIdeas: Egg Drop Project Ideas -- How to Drop Eggs Without Breaking
- Aero: Parachutes
- Almost Unschoolers: Non-Newtonian Fluid Egg Drop Protection
- University of Wisconsin: Lumpy Liquids and Squishy Solids