Question

An areoplane initially at rest, undergoes a constant acceleration on of 2.5m/second down the runway for 30sec before taking off​

Answer 1

I'll just assume that the question is what's the velocity of the airplane before it takes off because you haven't included a question. Where u: velocity, a: acceleration, t: time

`u = a * t \\ u = 2.5 * 30 \\ u = 70ms`