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I am looking at this question:

A stone is dropped into a river from a bridge 43.9 ill above the water. Another stone is thrown vertically down 1.00 s after the first is dropped. The stones strike the water at the same time. (a) What is the initial speed of the second stone?

I have the solution but one thing I don't understand is why the initial speed of the second stone isn't just 0 m/s?

If you're dropping something down, wouldn't the initial velocity start at 0 m/s and then increase as it falls?

user130306
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    The second stone was thrown vertically down. The point of the exercise is to figure out the speed at which it was thrown. – rogerl Jan 20 '22 at 22:55
  • sorry if this is a stupid question but that means there is a difference between thrown and dropped right? if it was dropped then the initial velocity would be 0? – user130306 Jan 20 '22 at 23:06
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    "Dropped" clearly means initial velocity zero. "Thrown" would imply initial velocity nonzero. In this case, it clearly means initial velocity nonzero since as you point out, if the initial velocity were zero the question would not have a solution. – rogerl Jan 20 '22 at 23:09
  • ok thanks. and what's the equivalent for the upwards direction? does 'shot vertically up' mean nonzero intial velocity? what phrase would imply an initial velocity of zero in the upwards direction? – user130306 Jan 20 '22 at 23:14
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    Throw would work fine there too. An upwards velocity of zero would again probably be just "dropped", since gravity always acts downwards :) – rogerl Jan 21 '22 at 00:25

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