An aircraft starts from rest and accelerates at 42.5m/s^2 until it takes off at the end of the runway. How long will it take the aircraft to travel down the 2.6km runway?

Answer is 11 seconds

km -> m

a=v²/2s
s=at²/2
t=sqrt(2s/a)

11 s

To find the time it takes for the aircraft to travel down the runway, we can use the equation:

\[ d = \frac{1}{2}at^2 \]

where:
d = distance traveled (2.6 km = 2600 m)
a = acceleration (42.5 m/s^2)
t = time

We need to rearrange the equation to solve for t:

\[ t^2 = \frac{2d}{a} \]

Substituting the given values, we get:

\[ t^2 = \frac{2 \times 2600}{42.5} \]
\[ t^2 = \frac{5200}{42.5} \]
\[ t^2 = 122.35 \]

Taking the square root of both sides, we find:

\[ t = \sqrt{122.35} \]
\[ t \approx 11 \text{ seconds} \]

Therefore, it will take approximately 11 seconds for the aircraft to travel down the 2.6 km runway.