Answer:
the length of the now stationary spacecraft = 89.65m
Explanation:
In contraction equation, Length contraction L is the shortening of the measured length of an object moving relative to the observer’s frame.
Thus, it has a formula;
L = L_o(√(1 - (v²/c²))
Where in this question;
L = 71m and v = 0.610 c
Thus;
71 = L_o (√(1 - ((0.61c)²/c²))
c² will cancel out to give;
71 = L_o (√(1 - 0.61²)
71 = L_o (√(1 - 0.61²)
71 = 0.792L_o
L_o = 71/0.792
L_o = 89.65m