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• so my favorite class in high school was physics

• they open my eyes to the facts

• that we can understand and predict so

• much of the everyday world around us

• using math and equations so today I want

• to revisit the classic high school

• physics egg drop competition where you

• have to build some sort of contraption

• around an egg to make sure it doesn't

• crack when it hits the ground originally

• I wanted to do a bunch of research and

• testing to find the single best way to

• win the competition every time but what

• I found out with that each competition

• sort of has different rules in some

• you're not allowed to use popcorn or

• parachutes and in others you win if your

• contraption is the smallest or the

• lightest or both so i'm going to show

• you five super easy options and then

• we'll talk about why each one works

• let's go crack some eggs

• ball the basic principles that you put

• your egg in the middle of a box that

• contains some kind of cushioning

• materials such as bubble wrap or packing

• peanuts or popcorn personally I think

• this one is the most boring but it works

• and that's why every shipping company

• ever shipped this way i'm using a ball

• here because it's more weight efficient

• in a box where you have unnecessary

• cushioning in the corners plus the

• stretchiness of the ball will help

• absorb assembly energy

• the moment of truth and we have an

• intact egg before I show you the other

• four ideas let's talk about the science

• behind landing with an uncracked egg so

• the starter you dropped your egg is up

• high and it's stationary so it has

• potential energy which is the energy

• associated with height so these red

• blocks represent the potential energy

• and the higher I go the more blocks of

• energy I start and then as the egg fall

• that potential energy is converted to

• kinetic energy which is the energy of

• speed so you start up high and every

• single block is over here as potential

• energy but as you start to fall and fall

• faster and faster every single block

• comes over here is kinetic energy or

• impact the ground and have all this

• energy in the form of speed that got to

• go somewhere now this broom represents

• the standing energy that holds an

• eggshell together it makes it hard so

• egg hits the ground do you introduce

• more energy than the binding energy of

• the molecule holding the hard eggshell

• together at any point you're going to

• break at that point so the question that

• becomes what can we do to keep our

• blocks below the broom because simply

• put below the broom your egg is safe

• anything above the broom and your egg is

• busted well there's two things we can do

• the first is that we can make this pile

• of green blocks not as tall this is why

• no matter what your contraption is to

• protect the egg if your rules allow it

• you should make a parachute the bigger

• the better and it does not have to be

• fancy this is like old-school army guys

• style just cut up

• bag little bit of string little bit of

• tape and just looking at this you can

• see the difference a parachute could

• make so the second thing you can do is

• not to remove any green blocks by

• out so if we say left to right as our

• time axis the more we could stretch out

• this impact event the more we can lower

• that high energy spike and this is a

• cool way to think about any two objects

• impacted the longer the duration of the

• impact the more you can spread out that

• force so stuff doesn't break so for

• example this is the point of car air

• steering wheel and stopping near

• instantaneously it stretches out the

• impact force overtime so you don't get a

• quick spite that exceeds the broom line

• for your skull this is exactly why long

• jumpers prefer to land it's sand and not

• on asphalt and why parkour runners will

• always roll after a big jump it's all

• about defusing the force over a longer

• period of time so what does that mean

• for our egg contraptions it surely is

• something to keep in mind because it can

• make it more intuitive for example to

• see why putting your egg in the middle

• of a jar of peanut butter which is a

• popular and not a very good idea isn't

• as good as putting your egg in the

• middle of a popcorn ball okay back to

• the bridge

• you

• so a lot of people like to build

• contraptions out of straws and in some

• competitions that's all you have to work

• with how you configure your straws

• depends a little bit on how stiff they

• are the good folks at wendys have fairly

• stiff straws which means I didn't have

• to use quite as many so my idea was to

• take six like three inch long straws and

• build a regular triangular pyramid and

• then put the egg in the middle and then

• I took two of the Wendy straws and join

• them together to sort of make a mega

• straw and I use this wide tape to help

• prevent it from buckling and then I made

• six of those mega straws and simply

• taped one to each edge of the pyramid so

• the main point here is that there are no

• straws pointing directly at the egg when

• it impacts the ground the force goes up

• the stiffness path through the straw I

• saw a ton of examples online where the

• straw was actually pointed at the a we

• could create a puncture load in our case

• we have this pyramid so all the loads

• path next to the egg so you don't get

• that primary impact three two one so

• you'll notice we've got a couple of

• broken pieces but that's okay because it

• took energy to make those breaks and

• that sort of protect the shell of the

• egg and receiving that energy so success

• ok so our egg finally broke but it took

• about 20 tries and you can see there's a

• lot of busted straws here all in all it

• was pretty resilient yeah

• so this one is a throwback to my NASA

• roots in 2004 the emmy our Rovers landed

• on Mars using giant airbags and even

• though Mars has one-third the gravity of

• Earth I figured it would still work I

• started by cushioning the egg in four

• little balloons that I barely filled up

• and then I blew up bigger balloons and

• then just tied it all together with some

• string and tape and then if there's any

• gaps in coverage you can just tape a

• balloon directly to the stream you just

• tied around in addition to the balloons

• extending the impact time this design

• benefits from a large cross-sectional

• area relative to his weight so in a

• sense it becomes its own parachute of

• course if your rules allow it you should

• still throw an additional parachute on

• it anyways stop it from

• I'm 2012 we landed another rover on Mars

• called curiosity but this one was too

• big to use airbags so we had to have a

• power to send pretty much like a jet