Help with a confusing free-fall motion physics problem?

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Jrohazn
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I'm taking physics for the first time, and I've been attempting the textbook problems, but I can't seem to get it.

1. West stands on the roof of a building, leans over the edge and drops a rock. Lindsay waits 1.25 s after West releases his rock and throws her own rock straight down at 28.0 m/s. Both rocks hit the ground simultaneously. Calculate the common height from which the rocks were released.
2. y=y0+vo(t)-1/2(g)t^2
I'm honestly not even sure how to do it. For Wes: 0=y0-1/2(g)t^2; y0=1/2gt^2
I'm confused on how to set up Lindsay's equation. I checked other people's answers on chegg, and they seem to set up vo as a positive vector, but I thought that since she's throwing down, that it would be negative? Can someone clear that up for me? And for time, would it be (1.25+t)?

Please help :(
 
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