Jawabanmu

2014-02-27T20:42:18+07:00
2014-02-27T20:54:56+07:00
L2 = l1 (1+alfa+delta t)
l2 = 80 ( 1 + 0,000017 x 50 )
l2 = 80 ( 1 + 0,00085 )
l2 = 80 ( 1,00085 )
l2 = 80,068 m

jdi pertmbhan pnjangnya adalah 80,068 m.