Posted by Wms on .
A helicopter is ascending vertically with a speed of 3.00 m/s. At a height of 70 m above the Earth, a package is dropped from a window. How much time (in seconds) does it take for the package to reach the ground? [Hint: The package's initial speed equals the helicopter's.]
This question was asked a few days ago, but perhaps not by you. The equation for height (above the ground, in meters) vs time (in seconds) is
y = 70 + 3 t - (g/2) t^2
Use g = 9.8 m/s^2 and solve for the time when y = 0. The quadratic equation will give you two answers. Take the positive one.