A helicopter hovers 200.0 meters over the ground and releases a relief packet. How much time does it take for the food packet to reach the ground?

Kinematics equation for a free fall of height h

h=0*t + (1/2) gt^2

where g=9.80655 m/s^2 is acceleration due to gravity

Express equation in terms of t

t=sqrt (2h/g)

=sqrt (2*200/9.80655)

=20/sqrt (9.80655)

=6.3866 seconds

=6.387 seconds (to four significant figures)

On Plato the answer is 6.4