# physics

posted by
**Brianna**
.

Two stones are thrown vertically up at the same time. The first stone is thrown with an initial velocity of 11.5 m/s from a 12th-floor balcony of a building and hits the ground after 4.0 s. With what initial velocity should the second stone be thrown from a 4th-floor balcony so that it hits the ground at the same time as the first stone? Assume equal height floors, and that in each case the stone is dropped from the same height as the ceiling.