Egg Drop Lab

I think that our capsule will work because we have crumpled paper, stuffing and air to provide a cushioning from the impact. These will increase the contact time for the capsule, will therefore decrease the force.

For the Eggrop lab, Brent and I used a plastic bag, slightly crumpled recycled paper, a paper plate, two rocks, cardboard, a plastic cup (with a lid) and stuffing (like from a plushie). We crumpled up the paper so that it wasn't dense, but it had some spring in it. We took the cup and filled it with the stuffing so that the egg was packed snuggly in the cup when we closed the lid. We filled the plastic bag with air and the crumpled paper and then placed the cup resting on the top and then tied the plastic bag shut. On the bottom of the bag, there is a plate glued flat with rocks glued to the plate, and then another piece of cardboard glued and taped over the rocks and paper plate. Our capsule's dimensions were 22cm x 21cm x 29cm.

The paper cushioning inside the bag and the stuffing inside the cup work as a crumple zone for the capsule, which increases the contact time for the egg. Increasing the contact time will reduce the force the ground puts on the capsule because time and force are inversely related. The rocks are at the bottom to make sure the whole system falls upright. Even though this adds to the mass, which will ultimately make the capsule fall with more acceleration and the momentum, but it forces the whole system to fall in the position we intend it to fall. We used a paper plate so that it would be easier to secure the rocks to the bag and we put the cardboard over the rocks make the bottom flat so that when it does hit the ground, it doesn't roll to the side. The awkward shape of the capsule will also hopefully increase air resistance.

Here are two force diagrams, the first showing the capsule in free fall and the second diagram showing the capsule as it hits the ground. As you can see the capsule is condensed because of its crush zone. The forces acting upon the capsule in free fall is the weight of the capsule and the air resistance. Since the weight is more than the air resistance, the capsule is accelerating downward, except when the capsule reaches terminal velocity, then the capsule will have balanced forces and will not be accelerating. The second diagram shows the capsule as it hits the ground. The forces acting upon are its weight and the force of the ground. Since the capsule is coming to a sudden stop, it is accelerating in the opposite direction so the force from the ground is greater than the weight of the capsule.

Luckily, our capsule was very successful  it did just as we hoped. The capsule properly crumpled in the right places, fell upright and kept the egg safe. The paper cushioning inside the bag and the stuffing inside the cup work as a crumple zone for the capsule, which increases the contact time for the egg. Even though we were successful, we still could've done some things to make it better. I had the idea of twisting the bag as it fell to keep it even more stable. Also, I think we should've had a rock hanging from a string on the bottom instad of rocks just glued to the bottom to be even more stable.