A stone is dropped into a river from a stationary balloon 405 m above water. Another stone is thrown vertically down 1.00 s after the first is dropped. The stones strike the water at the same time. Time initial speed of the second stone is (acceleration due to gravity g = 10 m/s2)
1
12.625 m/s
2
16.625 m/s
3
8.625 m/s
4
10.625 m/s