Question

A plane has a takeoff speed of 324km/h and requires 1.35km to reach that speed.

Determine the acceleration of the plane and the time required to reach this speed.[4]

Answer 1

If the plane is starting from rest, then the acceleration a that it needs in order to speed up to 324 km/h = 90.0 m/s over a distance of 1.35 km = 1350 m satisfies

(90.0 m/s)² = 2a (1350 m) ==> a = 3.00 m/s²

(use the kinematic equation, v ² - v₀² = 2a ∆x)

and the amount of time t needed to reach this speed is such that

90.0 m/s = (3.00 m/s²) t ==> t = 30.0 s

(v = v₀ + at )