4x=x2-x1=100m24=t2-t1=10s,L=0.98c 100-0.98×10 ≈-1.47×100m √1-0982 10-0.98c×100 ≈50.25s √1-0982x x x 100m, t t t 10s,u 0.98c  = 2 − 1 =  = 2 − 1 = = x x m 1 0 2 2 1 1.47 10 1 0.98 100 0.98 10  −  − −   −  = s c c t t 50.25 1 0.98 10 0.98 100 2 2 2 1  − −   −  =