delta L = Lo-Lo*sqrt(1-V^2/c^2
delta L = 0,3L
Lo = L
Lo-delta L = Lo*sqrt(1-V^2/c^2)
[(Lo - delta L)/Lo]^2 = 1-V^2/c^2
V^2/c^2 = 1- [(Lo - delta L)/Lo]^2
V^2 = c^2 [1- [(Lo - delta L)/Lo]^2]
V = c*sqrt(1- [(Lo - delta L)/Lo]^2)
... i podstawić delta L = 0,3L, Lo = L
albo jakoś tak, bo fizykę miałem 2 semestry temu