An airplane requires 420 m of runway to take off from an airstrip. If the plane starts from rest and it takes 32 s to lift off, with what velocity does it leave the ground? What was the average acceleration of the plane?

Answer 1

Δx = vi*Δt+(1/2)aΔt²
vi=0
so
Δx = (1/2)aΔt²
a=2Δx/Δt²
=2*420/(32²)
=(105/128) m/s²

vf=aΔt
=(105/128)*32
=26.25 m/s (not extremely fast for a plane)