Jawabanmu

2014-03-13T20:24:45+07:00
L2 = L1 (1+α.Δt)
     = 30m (1+0,000011/°C.(40'C-10'C))
     = 30m (1+
0,000011/°C.30'C)
     = 30m (1+0,00033)
     = 30m + 0,0099m
L2 = 30,0099m

ΔL = L2 - L1
     = 30,0099m - 30m
ΔL = 0,0099m

Jadi , jarak antara 2 rel adalah 0,0099 x 2 = 0,0198m
GOOD LUCK
2 4 2