# Cross a barrier with a drone [closed]

How fast does a multi-copter drone need to fly in order to freefall on the other side of a highway if:

Drone weight - 15kg, 20kg
Highway width - 70 ft
altitude above ground - 200 ft, 300 ft, not determined

Thanks!

• This looks like homework with no attempt at a solution. – Transistor Jun 27 '19 at 16:58
• And if it's unpowered, neglecting friction, then it's not really an aviation question as it doesn't matter if it's a drone or a cannonball, it's a basic projectile physics question. – fooot Jun 27 '19 at 17:35
• @Transistor homework or research for a smuggling project :') – Quentin H Jun 28 '19 at 8:08

solved for t this is
with a being the acceleration (in this case a = g = 9.81 m/s) and s elevation in meters above ground.