Answer
The length according to the pilot on the spaceship is $56.0~m$
Work Step by Step
Let $L = 40.0~m$
We can find the length $L_0$ measured by the pilot on the spaceship:
$L = L_0~\sqrt{1-\frac{v^2}{c^2}}$
$L_0 = \frac{L}{\sqrt{1-\frac{v^2}{c^2}}}$
$L_0 = \frac{40.0~m}{\sqrt{1-\frac{(0.70~c)^2}{c^2}}}$
$L_0 = 56.0~m$
The length according to the pilot on the spaceship is $56.0~m$
