DAY 4

Big rock off the coast of Kauai (one of the Hawaiian Islands). Summer 2018. We really loved Kauai - lots of hiking and small towns.
The best way to cheer yourself up
Is to cheer someone else up.
- Mark Twain

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5 MORE THINGS TO DO + WORTH A CLOSER LOOK + PHYSICS EXPERIMENT THEORETICAL ANSWER


5 More Things To Do

1. Ponder Everyday Phrases. How did they start? "Turn out the light" - are you really turning anything? Why do you "take" a shower but "get" a haircut?

2. Pick up some old phrases no longer in use. See if you can bring them back by using them with family & friends. "That's really rad!" "Groovy!" "So phat!"

3. Go online and find acting tutorials on accents. Pick one and practice till you're good. Try holding whole conversations with your friends in that accent.

4. Learn some everyday phrases in a new language. Pick a language we don't teach in school. Use the phrases with family and friends. In bocca al lupo!

5. It's almost time to go shopping. Don't worry if you weren't able to stock up on toilet paper. Most grocery stores get deliveries twice a week. Now that the panic has died down, it'll soon be time to go shopping.


Worth a Closer Look


As we walked up to the entrance to the visitor center for Meteor Crater in Arizona, I happened to look to my left and saw what appeared to be a large landscape painting. I looked again and realized it was an opening in the wall - I was looking outside. The illusion was perfect from a distance. I wonder if it was designed for that purpose.




Physics Experiment Answer

I hope you had fun with the overhang experiment. Send me pics of the results by email - I can post them tomorrow!

Assuming that the objects you picked don't bend, and that there is not much friction between them, the theoretical overhang is about 0.92 of the length of the object. The best way to proceed is to push the top object over until it's just about to fall off, then push the second over (with the first one still in place on top) until it's about to fall off. Finally, push the bottom one out (with the other two still in place on top) until it's about to fall off.

See below for an explanations & diagrams of the theoretical answer. Bear in mind, if there is friction or the shapes are odd you might be able to beat 0.92.
Push the top object over. It will just start to fall when it's CM is at the edge of the object below it: halfway out.
Locate the center of mass of the top two objects. It's halfway between the top two objects, or 0.25 back from the edge.
Slide the second object out (with the first in place on top) until their mutual CM is just at the edge: 0.75 out.
Calculate the CM of the three object. Mass times position of each object, added together and divided by the total mass.
The CM of the three objects is about 0.92 back from the edge of the top object.
Shift the bottom object out (with the other two in place on top) out until it just starts to tip. It should have about 0.92 overhang now.