posted by Fabian .
A helicopter is ascending vertically with a speed of 5.20 m/s. At a height of 125 m above the Earth, a package is dropped from a window. How much time does it takes the package to hit the ground? [Hint: The package's initial speed equals the helicopter's]
h=v²/2g=5.2²/2• 9.8=1.38 m.
t=sqrt(2•H/g) = sqrt(2•126.38/9.8)=5.08 s.