How Long Before Overhead Should Supplies Be Dropped from a Plane?

[Natali]

Homework Statement

The pilot of an airplane traveling 160 km/h wants to drop supplies to flood victims isolated on a patch of land 120 m below. The supplies should be dropped how many seconds before the plane is directly overhead?

Homework Equations

equations of motion

The Attempt at a Solution

i don't know what 2 plug in...

 

[LowlyPion]

Homework Statement

The pilot of an airplane traveling 160 km/h wants to drop supplies to flood victims isolated on a patch of land 120 m below. The supplies should be dropped how many seconds before the plane is directly overhead?

Homework Equations

equations of motion

The Attempt at a Solution

i don't know what 2 plug in...

They want to know how long it takes to drop 160m.

X = 1/2 g t²