Answer:
0.8216c
Explanation:
Using the relationship
L' = L√(1 - v²/c²)
where
L = original length,
L' = observed length,
v = velocity,
c =speed.
L'/L = 0.57
Then
0.57 = √(1 - v²/c²)
1 - v²/c² = 0.57² = 0.3249
v²/c² = 1 - 0.3249 = 0.6751
v² = 0.6751c²
v = c√0.6751 = 0.8216c
Explanation:
