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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? (??)

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.

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.

@Michael Mendrin
–
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

@John M.
–
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.

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":

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

@Satvik Golechha
–
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.

@Michael Mendrin
–
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

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This discussion board is a place to discuss our Daily Challenges and the math and science related to those challenges. Explanations are more than just a solution — they should explain the steps and thinking strategies that you used to obtain the solution. Comments should further the discussion of math and science.

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## Comments

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

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

Can you tell now why this won't happen?

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

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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

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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.

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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

fasterthan the wind! Many say this is impossible, but it's been done, the record being almostthreetimes downward wind speed.Log in to reply

TEN TIMESfaster than the wind. But before that your cart will probably fly apart... LolLog in to reply

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.

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I have a better idea:

s

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

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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":

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

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still have MOMENTUM? without MASS?!?

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

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s

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