Under the ruler 2: the ground moves

Why do people test a wind-powered cart on a treadmill? Wind is the relative movement between air and something else (usually the ground). We usually think of the ground being stationary and the air moving, but it works just as well to have the air stationary and the ground moving.

Category:

Science & Technology

Tags:

• DWFTTW
• DDWFTTW
• newton
• physics
• mechanics
• wheels
• gears
• relative
• velocity
• experiment
• paper
• cotton reel
• treadmill
• toys

[mrblanco101]

just had a thought. . you say this is like the dwfttw.

but with this the cart is a gear system. it is geared to move say twice as fast as the ruler, and when you move the ruler you have to apply twice as much force than if it was not geared, so it moves twice as fast.

with the wind, the wind cannot simply apply twice as much force to make a geared cart move faster than it.

The dwfttw may work, but surly not on this principle?

[coolaun]

The DDWFTTW cart takes its energy from the wind, or more precisely the relative motion of air and ground. It is correct that the faster the DDWFTTW cart goes, the less force it will produce, as in any system of gearing. However, wind at a certain velocity does not produce a fixed amount of energy. It's perfectly easy to increase the force you gain from the wind: just make the propeller bigger.

[jacobjosko]

i love your voice it calming i love all your teddies and the animals

[debbie0902]

This is a really cool video.

I love your voice

[banjokazooiification]

your voice makes my heartrate drop

[TheEclipsedsun]

Ohhhhh I've been watching this video for three years now and I finally get it!! All you did was make the wind (or what propels the cart forward) visible by replacing it with a ruler. Brilliant absolutely brilliant

[welovepies]

Please come back.

[N05h00b135]

im so relieved im not the only one who thinks this guys voice is awesome

[johnqpublic912]

i was sold once i saw the cosby sweater

[L33tHackzor]

Very informative! thank you!

[spineboy]

Hmm - so the friction drives the direction. If the top wheel was the smallest, I think it might go in the other direction.

[MrRubixTV]

@TheLoganwade

Actually if you look more carefully, you will see that Ethel has her face pointing towards the left of the screen. As @coolaun motions with his hands from right to left, Ethel would move in the direction her face is pointing. Thus she would feel the wind on her face.

I do hope that in the future you will examine videos more carefully and cease to make false claims against such a good video.

[TheLoganwade]

First of all, Ethel wouldn't feel the wind on her face if she was on the treadmill facing that way. She would feel it on her butt. :) Second, you really should keep making videos. You're one of those few people that it wouldn't matter if your videos were about paint drying, it would still be a hit because people love your relaxing voice. and I'd like to see where you keep Terry and the other animals. :)

[L3GiTxShOt]

lol chicken called carlos... good name