speedboat

[squarebear]

Please could you scientific lot settle a family argument please.

Imagine you are travelling in a speedboat moving quickly through the sea and you are stood near the back of the boat. For some reason, you decide to jump up in the air. Would you land back in the speedboat or in the sea?

I think you would land back in the boat as you are travelling at the same speed as the boat. My wife thinks you would be caught by the air and be thrown backwards.

[New Judge]

Depends how high you jump!

In a vacuum you would land at the same point back on the boat. However, in air the air resistance will immediately slow you down as soon as you left the deck. You would land either back in the boat, but slightly nearer the stern, or you would travel over the transom and in the drink. It is how long you stay in the air which will determine how much the air resistance slows you down.

[R1Geezer]

This is a traditional thought experiment. Usually air resistance is taken out of the equation so in a vacuum, as the judge says you'd land on the same spot as you left. This is often done with the jump inside a train carraige.

[squarebear]

That makes sense guys. I was equating it to jumping inside a train carriage. You don't find yourself at the back of the carriage when you jump inside a train.

I guess the air in the train carriage is also moving at the same speed whereas the air around a speedboat is (relativel) still.

I guess this means I have to do the washing up then!

[R1Geezer]

Not really SQB, you see the whole thing is invalid if you leave the air in. What does she reckon with the train? if she thinks you don't land back where you took off then you have the moral victory!

[squarebear]

I'll have to ask her Geezer. Just hope she doesn't see this thread before I see her.

[ladyalex]

You could try to replicate the scenario with yourself walking backwards holding a ball. Throw the ball in the air and keep in walking backwards and see where the ball lands...in your hands or on the floor.
Then walk faster to try to replicate a speedboat.

[wildwood]

Let this be a lesson to you, always listen to She Who Must Be Obeyed. Even if you're right, you're still wrong. I though every married man knew this (°¿°)

Even on a train, if you want to be pedantic, you land behind where you jumped from because you temporarily loose traction.