Jawabanmu

2014-08-13T22:14:18+07:00
V=r/t
t=r/v ----> t=200m / 20m/s = 10s
2014-08-13T22:30:12+07:00
Dik v = 20m/s dan s = 200 m
dit t?
rumus awal v = s/t
20 = 200 / t
20t = 200
t = 200 : 20 = 10 s