I've read that solar wind consists of hydrogen atoms that are, near the Earth, travelling at about 450 km/s. This is only 3/4 of the Sun's escape velocity, but then the Earth is also 150 million km away from the Sun.
Does this mean that all those particles will eventually fall back down like a ball launched from a catapult? Even if said ball was launched at say 9 km/s, it's still less than the 11.2 required to escape so it'll eventually fall back down.
Best Answer
The escape speed at 150 Gm is about 42 km/s, namely $\sqrt{2}$ times Earth's orbit velocity of bout 30 km/s. This is vastly exceeded by the value of 450 km/s that you give, without reference. The conclusion is that the final whereabouts of the solar wind is not restricted by the Sun's gravity.
As to where the matter of the solar wind ends up, I would suspect in the Oort cloud but I give my conjecture for an expert opinion.