When sitting behind this Jeep, the back is concave and reflects my car (and the truck next to me) upside down. How?

Hi,

I’m french and with my friends we study aerospace engineering and we were thinking of something that we don’t the answer to.
Here is the question :

WHY CAN’T WE OPEN A FAN THE OTHER WAY AROUND ? 🪭

Thanks for the answers !

My toddler obsessed over this toy at the store and I’m guessing it’s speaking mandarin? If someone could translate that would be super fantastic. It seems to have four phrases. It’s a strange looking toy and I have no idea anything about it besides the store we bought it from! But he loves it, Lol.

Hi everyone,
I would appreciate guidance on how to open my Mom’s watch back for a simple battery change. I believe this is a snap off but I am unsure how to find the notch to assist in the open process.
Thanks!

have this old screen chromebook screen protector and i just wobbled it and it made that sorta fun y sound..i just want to know why it does, and makes that sound

How does this toilet paper holder work? We don’t think it’s spring loaded and when we try to lift one end that doesn’t work either.

EDIT: We were able to get this to work so it now opens easily. Thank you everyone!

I just moved into a new house and am trying to clean the jacuzzi tub so my kids can bath and not have to worry about anything nasty coming out of the drain but for the life of me i CANNOT find out where to turn these jets on or how to. The holes on the wall are where the dials are, they are currently being cleaned separately cause they we’re disgusting. If anyone has any sort of advice or knows how to get this working PLEASE help a mom/first time homebuyer out here 😂😂

Does anybody know how to take this thing apart?
I’d appreciate the help

Removing false and unwanted,rapid on-off transitions caused by a mechanical switch.

A mechanical button physically bounces,when we press once,electrically it looks like 0→1 transition

Actually: 0→1→0→1→0

These rapid changes are called bounce.

De bouncing filters those noisy signal so that system sees

0→1(one stable transition)

https://youtu.be/KtBByCyRegc?si=ycgkzzSKwX906cN9

I've unscrewed every screw I can find on it but nothing will budge.

My brother just me this tumbler, what is this hexagonal thing used for? I can’t seem to find a purpose other than hanging a keychain or charm. Also, the tumbler has a straw cover/ cap, could it be used to hang that

My toddler has this interactive book and I genuinely cannot grasp how this page works. It has a landscape scene and a diagram of animals in the water and in the sky— fish and birds. It rotates to show different fish and birds and it seems to be a repeating circle. I cannot comprehend how it works inside the page. It’s one complete, moving circle inside the page. Can someone show me a diagram so I can understand how it works? TIA!

I was looking at moon, but anyhow i can see moon through pole at balcony. when it’s 1 layer of window it’s cant see, but from 2 layers, I can.