Question

Hawk Eye shoots his first arrow from a cliff of 49m high. One second later he shoots his second arrow after the first one. Both the arrows reach the ground at the same time. With what speed did he shoot the second arrow.

Answer 1

first arrow: h = 49 - 4.9t^2
so, it takes √10 = 3.16 seconds to hit.
That means the 2nd arrow has to hit in 2.16 seconds. Using that value for t, find v such that
49 + vt - 4.9t^2 = 0