Answer:
is the distance from the target before which the pilot must release the canister.
Step-by-step explanation:
Given:
- height of the plane,

- horizontal speed of plane,

Time taken by the canister to hit the ground:
using equation of motion

where:
initial vertical velocity of the canister = 0 (since the the object is dropped from a horizontally moving plane)
time taken to hit the ground


Now the horizontal distance travelled by the canister after dropping:


is the distance from the target before which the pilot must release the canister.