Jawabanmu

2014-08-04T15:48:25+07:00
Kecepatan rata-rata
= s total
    t total
= 250
   10 s
=25

kelajuan rata-rata
= 0,25 km :  0,00277777778 jam
= 0,000694444445 km/jam

2 4 2
2014-08-04T16:29:29+07:00
Maaf, cuma tau kecepatan rata-ratanya

 s_{1}
 s_{2}
t = 10 s

v =  \frac{s}{t}
  =  \frac{200 m + 50 m}{10 s}
  =  \frac{250}{10}
  = 25  ms^{-1}