# $\forall \exists \emptyset | \Re$

Problem, motorboat companies?

Note by John M.
6 years, 6 months ago

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Water is diamagnetic. So, I think it wont be possible.

- 6 years, 6 months ago

Actually, that's not the reason why. See Conceptual Physics I.

Can you tell now why this won't happen?

- 6 years, 6 months ago

How do you know it won't go backward? :P

- 6 years, 6 months ago

Eh, but you can blow your own sail with a fan on the boat, and move the boat forward. That can actually work. So, maybe motorboat companies should give this one another look? (??)

Fan Sail

- 6 years, 6 months ago

Dam that pic's on point! Ok now we're getting serious:

So, here's what I think (and I think you know): The propeller, displacing the air forward, pushes itself backwards (N3L), which is the same case with the magnet but in a more indirect way. But the aerodynamics work with pressure in complicated ways to actually make this work. Buut... all this jazz compared to the motor boat, which spins a smaller fan under water much more effectively (even having a "push-off" effect that everyone relies on when trying to disprove rocket science), so yeah... Motorboat companies ain't goin bankrupt any time soon.

- 6 years, 6 months ago

No, not likely any time soon. However, this does remind me of a real interesting physics problem, which is that it's possible for a cart, fitted with a propeller that connects to the wheels mechanically, to go downwind faster than the wind! Many say this is impossible, but it's been done, the record being almost three times downward wind speed.

- 6 years, 6 months ago

Oh lol that's a no brainer for me - I know why sailing upwind is faster, so I can treat the propellers as sails and apply the same principle and BAM! you can go TEN TIMES faster than the wind. But before that your cart will probably fly apart... Lol

- 6 years, 6 months ago

Uh, it's downwind, John. With a sailing boat, going directly downwind, well, it's hard to go faster than the wind itself. Do you know of a way to go faster downwind? In theory, if a sailboat is going as fast as the wind, with the wind directly at it's back, then onboard, one wouldn't feel much of any wind at all in any direction.

But, yes, when tacking, which is going crosswinds, making clever use of sails, re-direction, and keels, one can go faster than the wind itself. Maybe counterintuitive for non-sailors.

- 6 years, 6 months ago

I have a better idea:

s

- 6 years, 6 months ago

I was like "Whaat?!", Trolololl!!! Light has no mass, so by conservation of linear momentum, that troll won't go forward. -_-

- 6 years, 6 months ago

"Light has no mass..."

Be careful what you state there. Light is affected by gravity (evidence - light curves around a black hole and stars), meaning it interacts with the higgs field - so, it does have some mass.

Massles particles - tachyons -are yet to be discovered. And remember the implications of "massless":

$a=\frac{F_{net}}{m}\Rightarrow a=\frac{F_{net}}{0}\Rightarrow a \rightarrow \infty$

- 6 years, 6 months ago

Actually, even though photons have no mass, they can still have energy and momentum, so that troll can go forward. But just not very speedily.

- 6 years, 6 months ago

no no hold on a second, what about what I said above? light b... wait. is this because space bends and light just follows it and thus light doesnt bend but it bends relative to other space... ?? errrr

- 6 years, 6 months ago

Wait.. WHAT?

still have MOMENTUM? without MASS?!?

uum.... Ok I'm outa here.

- 6 years, 6 months ago

Yes sir, I kinda' knew that, I was just trying to troll an already trolled troll trolling trollers... :-P

- 6 years, 6 months ago

And I was trying to troll a troll that trolled a trolled troll trolling trollers...

s

- 6 years, 6 months ago

It takes around 10000 bulbs to lift a sock

- 6 years, 6 months ago